diff options
Diffstat (limited to 'c.html.markdown')
| -rw-r--r-- | c.html.markdown | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/c.html.markdown b/c.html.markdown index 84856b32..c89f2b88 100644 --- a/c.html.markdown +++ b/c.html.markdown @@ -92,7 +92,7 @@ int main() { printf("%zu\n", sizeof(int)); // => 4 (on most machines with 4-byte words) - // If the argument of the `sizeof` operator an expression, then its argument + // If the argument of the `sizeof` operator is an expression, then its argument // is not evaluated (except VLAs (see below)). // The value it yields in this case is a compile-time constant. int a = 1; @@ -154,7 +154,7 @@ int main() { int multi_array[2][5] = { {1, 2, 3, 4, 5}, {6, 7, 8, 9, 0} - } + }; //access elements: int array_int = multi_array[0][2]; // => 3 @@ -215,7 +215,7 @@ int main() { z = (a > b) ? a : b; // => 10 "if a > b return a, else return b." //Increment and decrement operators: - char *s = "iLoveC" + char *s = "iLoveC"; int j = 0; s[j++]; // => "i". Returns the j-th item of s THEN increments value of j. j = 0; @@ -251,7 +251,7 @@ int main() { // While loops exist int ii = 0; while (ii < 10) { //ANY value not zero is true. - printf("%d, ", ii++); // ii++ increments ii AFTER using it's current value. + printf("%d, ", ii++); // ii++ increments ii AFTER using its current value. } // => prints "0, 1, 2, 3, 4, 5, 6, 7, 8, 9, " printf("\n"); @@ -259,7 +259,7 @@ int main() { int kk = 0; do { printf("%d, ", kk); - } while (++kk < 10); // ++kk increments kk BEFORE using it's current value. + } while (++kk < 10); // ++kk increments kk BEFORE using its current value. // => prints "0, 1, 2, 3, 4, 5, 6, 7, 8, 9, " printf("\n"); @@ -367,7 +367,7 @@ int main() { // This works because arrays often decay into pointers to their first element. // For example, when an array is passed to a function or is assigned to a pointer, // it decays into (implicitly converted to) a pointer. - // Exceptions: when the array is the argument of the `&` (address-od) operator: + // Exceptions: when the array is the argument of the `&` (address-of) operator: int arr[10]; int (*ptr_to_arr)[10] = &arr; // &arr is NOT of type `int *`! // It's of type "pointer to array" (of ten `int`s). @@ -376,7 +376,7 @@ int main() { // or when it's the argument of the `sizeof` or `alignof` operator: int arr[10]; int *ptr = arr; // equivalent with int *ptr = &arr[0]; - printf("%zu %zu\n", sizeof arr, sizeof ptr); // probably prints "40, 4" or "40, 8" + printf("%zu, %zu\n", sizeof arr, sizeof ptr); // probably prints "40, 4" or "40, 8" // Pointers are incremented and decremented based on their type @@ -387,7 +387,7 @@ int main() { // You can also dynamically allocate contiguous blocks of memory with the // standard library function malloc, which takes one argument of type size_t // representing the number of bytes to allocate (usually from the heap, although this - // may not be true on e. g. embedded systems - the C standard says nothing about it). + // may not be true on e.g. embedded systems - the C standard says nothing about it). int *my_ptr = malloc(sizeof(*my_ptr) * 20); for (xx = 0; xx < 20; xx++) { *(my_ptr + xx) = 20 - xx; // my_ptr[xx] = 20-xx @@ -405,7 +405,7 @@ int main() { // Strings are arrays of char, but they are usually represented as a // pointer-to-char (which is a pointer to the first element of the array). // It's good practice to use `const char *' when referring to a string literal, - // since string literals shall not be modified (i. e. "foo"[0] = 'a' is ILLEGAL.) + // since string literals shall not be modified (i.e. "foo"[0] = 'a' is ILLEGAL.) const char *my_str = "This is my very own string literal"; printf("%c\n", *my_str); // => 'T' @@ -454,6 +454,12 @@ void str_reverse(char *str_in) } } +/* +char c[] = "This is a test."; +str_reverse(c); +printf("%s\n", c); // => ".tset a si sihT" +*/ + //if referring to external variables outside function, must use extern keyword. int i = 0; void testFunc() { @@ -467,11 +473,7 @@ void testFunc() { } //**You may also declare functions as static to make them private** -/* -char c[] = "This is a test."; -str_reverse(c); -printf("%s\n", c); // => ".tset a si sihT" -*/ + /////////////////////////////////////// // User-defined types and structs @@ -567,7 +569,7 @@ typedef void (*my_fnp_type)(char *); '\b' // backspace character '\0' // null character. Usually put at end of strings in C lang. // hello\n\0. \0 used by convention to mark end of string. -'\\' // backspace +'\\' // backslash '\?' // question mark '\'' // single quote '\"' // double quote |