From e1ac6209a8d3f43e7a018d79454fb1095b3314c0 Mon Sep 17 00:00:00 2001 From: Zachary Ferguson Date: Wed, 7 Oct 2015 23:45:01 -0400 Subject: [c/en] Added a section for header files. Added a section for header files. Included a discussion of what belongs in a header file and what does not. --- c.html.markdown | 50 +++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index db2ac930..f1201eac 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -6,7 +6,7 @@ contributors: - ["Árpád Goretity", "http://twitter.com/H2CO3_iOS"] - ["Jakub Trzebiatowski", "http://cbs.stgn.pl"] - ["Marco Scannadinari", "https://marcoms.github.io"] - + - ["Zachary Ferguson", "https://github.io/zfergus2"] --- Ah, C. Still **the** language of modern high-performance computing. @@ -630,6 +630,54 @@ typedef void (*my_fnp_type)(char *); ``` +Header files are an important part of c as they allow for the connection of c +source files and can simplify code and definitions by seperating them into +seperate files. + +Header files are syntaxtically similar to c source files but reside in ".h" +files. They can be included in your c source file by using the precompiler +command #include "example.h", given that example.h exists in the same directory +as the c file. + +```c +/* A safe guard to prevent the header from being defined too many times. This */ +/* happens in the case of circle dependency, the contents of the header is */ +/* already defined. */ +#ifndef EXAMPLE_H /* if EXAMPLE_H is not yet defined. */ +#define EXAMPLE_H /* Define the macro EXAMPLE_H. */ + +/* Other headers can be included in headers and therefore transitively */ +/* included into files that include this header. */ +#include + +/* Like c source files macros can be defined in headers and used in files */ +/* that include this header file. */ +#define EXAMPLE_NAME "Dennis Ritchie" +/* Function macros can also be defined. */ +#define ADD(a, b) (a + b) + +/* Structs and typedefs can be used for consistency between files. */ +typedef struct node +{ + int val; + struct node *next; +} Node; + +/* So can enumerations. */ +enum traffic_light_state {GREEN, YELLOW, RED}; + +/* Function prototypes can also be defined here for use in multiple files, */ +/* but it is bad practice to define the function in the header. Definitions */ +/* should instead be put in a c file. */ +Node createLinkedList(int *vals, int len); + +/* Beyond the above elements, other definitions should be left to a c source */ +/* file. Excessive includeds or definitions should, also not be contained in */ +/* a header file but instead put into separate headers or a c file. */ + +#endif /* End of the if precompiler directive. */ + +``` ## Further Reading Best to find yourself a copy of [K&R, aka "The C Programming Language"](https://en.wikipedia.org/wiki/The_C_Programming_Language) -- cgit v1.2.3 From 3c02fdb8e496816b0fd615e029fad4a8ed9f4585 Mon Sep 17 00:00:00 2001 From: Zachary Ferguson Date: Wed, 7 Oct 2015 23:49:46 -0400 Subject: Revert "[c/en] Added a section for header files." This reverts commit e1ac6209a8d3f43e7a018d79454fb1095b3314c0. --- c.html.markdown | 50 +------------------------------------------------- 1 file changed, 1 insertion(+), 49 deletions(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index f1201eac..db2ac930 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -6,7 +6,7 @@ contributors: - ["Árpád Goretity", "http://twitter.com/H2CO3_iOS"] - ["Jakub Trzebiatowski", "http://cbs.stgn.pl"] - ["Marco Scannadinari", "https://marcoms.github.io"] - - ["Zachary Ferguson", "https://github.io/zfergus2"] + --- Ah, C. Still **the** language of modern high-performance computing. @@ -630,54 +630,6 @@ typedef void (*my_fnp_type)(char *); ``` -Header files are an important part of c as they allow for the connection of c -source files and can simplify code and definitions by seperating them into -seperate files. - -Header files are syntaxtically similar to c source files but reside in ".h" -files. They can be included in your c source file by using the precompiler -command #include "example.h", given that example.h exists in the same directory -as the c file. - -```c -/* A safe guard to prevent the header from being defined too many times. This */ -/* happens in the case of circle dependency, the contents of the header is */ -/* already defined. */ -#ifndef EXAMPLE_H /* if EXAMPLE_H is not yet defined. */ -#define EXAMPLE_H /* Define the macro EXAMPLE_H. */ - -/* Other headers can be included in headers and therefore transitively */ -/* included into files that include this header. */ -#include - -/* Like c source files macros can be defined in headers and used in files */ -/* that include this header file. */ -#define EXAMPLE_NAME "Dennis Ritchie" -/* Function macros can also be defined. */ -#define ADD(a, b) (a + b) - -/* Structs and typedefs can be used for consistency between files. */ -typedef struct node -{ - int val; - struct node *next; -} Node; - -/* So can enumerations. */ -enum traffic_light_state {GREEN, YELLOW, RED}; - -/* Function prototypes can also be defined here for use in multiple files, */ -/* but it is bad practice to define the function in the header. Definitions */ -/* should instead be put in a c file. */ -Node createLinkedList(int *vals, int len); - -/* Beyond the above elements, other definitions should be left to a c source */ -/* file. Excessive includeds or definitions should, also not be contained in */ -/* a header file but instead put into separate headers or a c file. */ - -#endif /* End of the if precompiler directive. */ - -``` ## Further Reading Best to find yourself a copy of [K&R, aka "The C Programming Language"](https://en.wikipedia.org/wiki/The_C_Programming_Language) -- cgit v1.2.3 From 9796759379d77a848ef84f8c1019672b87b90822 Mon Sep 17 00:00:00 2001 From: himanshu81494 Date: Thu, 8 Oct 2015 14:44:10 +0530 Subject: Update c.html.markdown --- c.html.markdown | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index db2ac930..b99cfe84 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -472,7 +472,22 @@ char c[] = "This is a test."; str_reverse(c); printf("%s\n", c); // => ".tset a si sihT" */ - +//as we can return return only one variable +//to change values of more than one variables we use call by reference +void swapTwoNumbers(int *a, int *b) +{ +int temp = *a; +*a = *b; +*b = temp; +} +/* +int first = 10; +int second = 20; +printf("first: %d\nsecond: %d\n", first, second); +swapTwoNumbers(&first, &second); +printf("first: %d\nsecond: %d\n", first, second); +// values will be swapped +*/ // if referring to external variables outside function, must use extern keyword. int i = 0; void testFunc() { -- cgit v1.2.3 From 626ee03fc3ca27698044db118bd53f563d22ccd0 Mon Sep 17 00:00:00 2001 From: himanshu81494 Date: Thu, 8 Oct 2015 14:45:16 +0530 Subject: Update c.html.markdown --- c.html.markdown | 1 + 1 file changed, 1 insertion(+) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index b99cfe84..8e1675bb 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -6,6 +6,7 @@ contributors: - ["Árpád Goretity", "http://twitter.com/H2CO3_iOS"] - ["Jakub Trzebiatowski", "http://cbs.stgn.pl"] - ["Marco Scannadinari", "https://marcoms.github.io"] + - ["himanshu", "https://github.com/himanshu81494"] --- -- cgit v1.2.3 From e8248af13431ca87786fff17a605189c69aacf15 Mon Sep 17 00:00:00 2001 From: himanshu81494 Date: Thu, 8 Oct 2015 15:31:40 +0530 Subject: Update c.html.markdown --- c.html.markdown | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index 8e1675bb..29bc5a5b 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -307,7 +307,25 @@ int main(void) { exit(-1); break; } - + + // using "goto" + typedef enum { false, true } bool; + // for C don't have bool as data type :( + bool disaster = false; + int i, j; + for(i=0;i<100;++i) + for(j=0;j<100;++j) + { + if((i + j) >= 150) + disaster = true; + if(disaster) + goto error; + } + error : + printf("Error occured at i = %d & j = %d.\n", i, j); + // this will print out "Error occured at i = 52 & j = 99." + + /////////////////////////////////////// // Typecasting /////////////////////////////////////// -- cgit v1.2.3 From e8e8b9c76fb578d3f8e90b90b3c8a1c59cf0e901 Mon Sep 17 00:00:00 2001 From: Andy B Date: Fri, 9 Oct 2015 15:48:21 +0100 Subject: [C/en] Accessing command line arguments in main --- c.html.markdown | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index db2ac930..345dca7f 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -27,6 +27,7 @@ Multi-line comments don't nest /* Be careful */ // comment ends on this line... */ // ...not this one! // Constants: #define +// Constants are written in all-caps out of convention, not requirement #define DAYS_IN_YEAR 365 // Enumeration constants are also ways to declare constants. @@ -56,6 +57,15 @@ int add_two_ints(int x1, int x2); // function prototype // Your program's entry point is a function called // main with an integer return type. int main(void) { + // your program +} + +// The command line arguments used to run your program are also passed to main +// argc being the number of arguments - your program's name counts as 1 +// argv is an array of character arrays - containing the arguments themselves +// argv[0] = name of your program, argv[1] = first argument, etc. +int main (int argc, char** argv) +{ // print output using printf, for "print formatted" // %d is an integer, \n is a newline printf("%d\n", 0); // => Prints 0 -- cgit v1.2.3 From c899b6605ef9667cb214c2163e7182ad41783be4 Mon Sep 17 00:00:00 2001 From: himanshu81494 Date: Fri, 9 Oct 2015 20:59:05 +0530 Subject: Update c.html.markdown --- c.html.markdown | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index 29bc5a5b..f35a2098 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -307,8 +307,9 @@ int main(void) { exit(-1); break; } - - // using "goto" + /* + using "goto" in C + */ typedef enum { false, true } bool; // for C don't have bool as data type :( bool disaster = false; @@ -323,7 +324,10 @@ int main(void) { } error : printf("Error occured at i = %d & j = %d.\n", i, j); - // this will print out "Error occured at i = 52 & j = 99." + /* + https://ideone.com/GuPhd6 + this will print out "Error occured at i = 52 & j = 99." + */ /////////////////////////////////////// @@ -491,13 +495,15 @@ char c[] = "This is a test."; str_reverse(c); printf("%s\n", c); // => ".tset a si sihT" */ -//as we can return return only one variable -//to change values of more than one variables we use call by reference +/* +as we can return only one variable +to change values of more than one variables we use call by reference +*/ void swapTwoNumbers(int *a, int *b) { -int temp = *a; -*a = *b; -*b = temp; + int temp = *a; + *a = *b; + *b = temp; } /* int first = 10; -- cgit v1.2.3 From e418849d7696bd91a144ccdff451025899ac10e0 Mon Sep 17 00:00:00 2001 From: Zachary Ferguson Date: Fri, 9 Oct 2015 11:52:08 -0400 Subject: [c/en] Added a section for header files. Added a section for header files. Included a discussion of what belongs in a header file and what does not. --- c.html.markdown | 50 +++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 49 insertions(+), 1 deletion(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index db2ac930..f1201eac 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -6,7 +6,7 @@ contributors: - ["Árpád Goretity", "http://twitter.com/H2CO3_iOS"] - ["Jakub Trzebiatowski", "http://cbs.stgn.pl"] - ["Marco Scannadinari", "https://marcoms.github.io"] - + - ["Zachary Ferguson", "https://github.io/zfergus2"] --- Ah, C. Still **the** language of modern high-performance computing. @@ -630,6 +630,54 @@ typedef void (*my_fnp_type)(char *); ``` +Header files are an important part of c as they allow for the connection of c +source files and can simplify code and definitions by seperating them into +seperate files. + +Header files are syntaxtically similar to c source files but reside in ".h" +files. They can be included in your c source file by using the precompiler +command #include "example.h", given that example.h exists in the same directory +as the c file. + +```c +/* A safe guard to prevent the header from being defined too many times. This */ +/* happens in the case of circle dependency, the contents of the header is */ +/* already defined. */ +#ifndef EXAMPLE_H /* if EXAMPLE_H is not yet defined. */ +#define EXAMPLE_H /* Define the macro EXAMPLE_H. */ + +/* Other headers can be included in headers and therefore transitively */ +/* included into files that include this header. */ +#include + +/* Like c source files macros can be defined in headers and used in files */ +/* that include this header file. */ +#define EXAMPLE_NAME "Dennis Ritchie" +/* Function macros can also be defined. */ +#define ADD(a, b) (a + b) + +/* Structs and typedefs can be used for consistency between files. */ +typedef struct node +{ + int val; + struct node *next; +} Node; + +/* So can enumerations. */ +enum traffic_light_state {GREEN, YELLOW, RED}; + +/* Function prototypes can also be defined here for use in multiple files, */ +/* but it is bad practice to define the function in the header. Definitions */ +/* should instead be put in a c file. */ +Node createLinkedList(int *vals, int len); + +/* Beyond the above elements, other definitions should be left to a c source */ +/* file. Excessive includeds or definitions should, also not be contained in */ +/* a header file but instead put into separate headers or a c file. */ + +#endif /* End of the if precompiler directive. */ + +``` ## Further Reading Best to find yourself a copy of [K&R, aka "The C Programming Language"](https://en.wikipedia.org/wiki/The_C_Programming_Language) -- cgit v1.2.3 From 79ced08e094e488eb21d026c882babc50d0ca168 Mon Sep 17 00:00:00 2001 From: Zachary Ferguson Date: Tue, 13 Oct 2015 11:05:20 -0400 Subject: Added Header title + Added a header file title * Changed ```c to ```h --- c.html.markdown | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index f1201eac..0c4916ac 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -630,6 +630,8 @@ typedef void (*my_fnp_type)(char *); ``` +### Header Files + Header files are an important part of c as they allow for the connection of c source files and can simplify code and definitions by seperating them into seperate files. @@ -639,7 +641,7 @@ files. They can be included in your c source file by using the precompiler command #include "example.h", given that example.h exists in the same directory as the c file. -```c +```h /* A safe guard to prevent the header from being defined too many times. This */ /* happens in the case of circle dependency, the contents of the header is */ /* already defined. */ -- cgit v1.2.3 From 223c8140a0392f3a0a33b93222597de7a68679e4 Mon Sep 17 00:00:00 2001 From: Awal Garg Date: Wed, 14 Oct 2015 20:41:36 +0530 Subject: clarify that args' names are not required in proto with obligatory conventional warning --- c.html.markdown | 2 ++ 1 file changed, 2 insertions(+) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index 3339032f..7c64cffe 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -54,6 +54,8 @@ int function_2(void); // Must declare a 'function prototype' before main() when functions occur after // your main() function. int add_two_ints(int x1, int x2); // function prototype +// although `int add_two_ints(int, int);` is also valid (no need to name the args), +// it is recommended to name arguments in the prototype as well for easier inspection // Your program's entry point is a function called // main with an integer return type. -- cgit v1.2.3 From 4599cd319fd409ddc697feffb607697285b26368 Mon Sep 17 00:00:00 2001 From: Awal Garg Date: Wed, 14 Oct 2015 20:44:45 +0530 Subject: [c/en] clarify common tripping point of newbies int foo () { printf("bar\n"); int x; // this is not valid in C89+ } --- c.html.markdown | 3 +++ 1 file changed, 3 insertions(+) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index 3339032f..8d4cfd93 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -74,6 +74,9 @@ int main (int argc, char** argv) /////////////////////////////////////// // Types /////////////////////////////////////// + + // All variables MUST be declared at the top of the current block scope + // we declare them dynamically along the code for the sake of the tutorial // ints are usually 4 bytes int x_int = 0; -- cgit v1.2.3 From 328ceb1a94f0fc6736e001ad0e7b6646173ca207 Mon Sep 17 00:00:00 2001 From: Elton Viana Date: Wed, 14 Oct 2015 21:44:42 -0300 Subject: Some extra information --- c.html.markdown | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index db2ac930..aaf176c1 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -221,7 +221,7 @@ int main(void) { 0 || 1; // => 1 (Logical or) 0 || 0; // => 0 - // Conditional expression ( ? : ) + // Conditional ternary expression ( ? : ) int e = 5; int f = 10; int z; @@ -291,6 +291,8 @@ int main(void) { for (i = 0; i <= 5; i++) { ; // use semicolon to act as the body (null statement) } + // Or + for (i = 0; i <= 5; i++); // branching with multiple choices: switch() switch (a) { -- cgit v1.2.3 From 27bb1a1e80b727b00b5ea8045d4bfa07eb1293bd Mon Sep 17 00:00:00 2001 From: Zachary Ferguson Date: Wed, 14 Oct 2015 21:59:42 -0400 Subject: Removed separate code section Removed the separate code section for header files --- c.html.markdown | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index 0c4916ac..5e8e13c1 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -628,9 +628,7 @@ typedef void (*my_fnp_type)(char *); // , | left to right // //---------------------------------------------------// -``` - -### Header Files +/******************************* Header Files ********************************** Header files are an important part of c as they allow for the connection of c source files and can simplify code and definitions by seperating them into @@ -640,8 +638,8 @@ Header files are syntaxtically similar to c source files but reside in ".h" files. They can be included in your c source file by using the precompiler command #include "example.h", given that example.h exists in the same directory as the c file. +*/ -```h /* A safe guard to prevent the header from being defined too many times. This */ /* happens in the case of circle dependency, the contents of the header is */ /* already defined. */ -- cgit v1.2.3 From 8417366a1b2d2b7bce35e2e4a4fdccee2a60f457 Mon Sep 17 00:00:00 2001 From: Zachary Ferguson Date: Thu, 15 Oct 2015 14:50:20 -0400 Subject: Cleaned up c file --- c.html.markdown | 4 ---- 1 file changed, 4 deletions(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index 7bb363b3..a8f71057 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -6,12 +6,8 @@ contributors: - ["Árpád Goretity", "http://twitter.com/H2CO3_iOS"] - ["Jakub Trzebiatowski", "http://cbs.stgn.pl"] - ["Marco Scannadinari", "https://marcoms.github.io"] -<<<<<<< HEAD - ["Zachary Ferguson", "https://github.io/zfergus2"] -======= - ["himanshu", "https://github.com/himanshu81494"] - ->>>>>>> refs/remotes/adambard/master --- Ah, C. Still **the** language of modern high-performance computing. -- cgit v1.2.3 From 2acf7822bdf45909d6c92fe30515b2a3b40e6c22 Mon Sep 17 00:00:00 2001 From: Brendan Batliner Date: Thu, 15 Oct 2015 16:34:53 -0500 Subject: Update c.html.markdown Added additional info on dynamically allocated arrays in C. --- c.html.markdown | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index a8f71057..b4129f7a 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -445,6 +445,17 @@ int main (int argc, char** argv) for (xx = 0; xx < 20; xx++) { *(my_ptr + xx) = 20 - xx; // my_ptr[xx] = 20-xx } // Initialize memory to 20, 19, 18, 17... 2, 1 (as ints) + + // Note that there is no standard way to get the length of a + // dynamically allocated array in C. Because of this, if your arrays are + // going to be passed around your program a lot, you need another variable + // to keep track of the number of elements (size) of an array. See the + // functions section for more info. + int size = 10; + int *my_arr = malloc(sizeof(int) * size); + // Add an element to the array + my_arr = realloc(my_arr, ++size); + my_arr[10] = 5; // Dereferencing memory that you haven't allocated gives // "unpredictable results" - the program is said to invoke "undefined behavior" @@ -530,6 +541,23 @@ swapTwoNumbers(&first, &second); printf("first: %d\nsecond: %d\n", first, second); // values will be swapped */ + +/* +With regards to arrays, they will always be passed to functions +as pointers. Even if you statically allocate an array like `arr[10]`, +it still gets passed as a pointer to the first element in any function calls. +Again, there is no standard way to get the size of a dynamically allocated +array in C. +*/ +// Size must be passed! +// Otherwise, this function has no way of knowing how big the array is. +void printIntArray(int *arr, int size) { + int i; + for (i = 0; i < size; i++) { + printf("arr[%d] is: %d\n", i, arr[i]); + } +} + // if referring to external variables outside function, must use extern keyword. int i = 0; void testFunc() { -- cgit v1.2.3 From 36fe7e1ccec6be05a98b9a8bee633073dca0d24d Mon Sep 17 00:00:00 2001 From: Brendan Batliner Date: Thu, 15 Oct 2015 16:38:42 -0500 Subject: Added example of printIntArray in C --- c.html.markdown | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index b4129f7a..3d632eab 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -557,6 +557,12 @@ void printIntArray(int *arr, int size) { printf("arr[%d] is: %d\n", i, arr[i]); } } +/* +int my_arr[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; +int size = 10; +printIntArray(my_arr, size); +// will print "arr[0] is: 1" etc +*/ // if referring to external variables outside function, must use extern keyword. int i = 0; -- cgit v1.2.3 From b31fda3a8e9f4d0ff021dc707f1e47af4add90ac Mon Sep 17 00:00:00 2001 From: Jody Leonard Date: Mon, 26 Oct 2015 19:38:36 -0400 Subject: Edit variable-length array example The current example seems to be trying to set a size for a char buffer, use fgets to populate that buffer, and then use strtoul to convert the char content to an unsigned integer. However, this doesn't work as intended (in fact, it results in printing "sizeof array = 0"), and so adapt to a simpler fscanf example. Also remove some ambiguous language in the example output. --- c.html.markdown | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) (limited to 'c.html.markdown') diff --git a/c.html.markdown b/c.html.markdown index 3d632eab..7c2386ef 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -148,15 +148,10 @@ int main (int argc, char** argv) printf("Enter the array size: "); // ask the user for an array size int size; fscanf(stdin, "%d", &size); - char buf[size]; - fgets(buf, sizeof buf, stdin); - - // strtoul parses a string to an unsigned integer - size_t size2 = strtoul(buf, NULL, 10); - int var_length_array[size2]; // declare the VLA + int var_length_array[size]; // declare the VLA printf("sizeof array = %zu\n", sizeof var_length_array); - // A possible outcome of this program may be: + // Example: // > Enter the array size: 10 // > sizeof array = 40 -- cgit v1.2.3