diff options
| -rw-r--r-- | bash.html.markdown | 20 | ||||
| -rw-r--r-- | javascript.html.markdown | 31 | ||||
| -rw-r--r-- | julia.html.markdown | 6 | ||||
| -rw-r--r-- | objective-c.html.markdown | 104 | ||||
| -rw-r--r-- | scala.html.markdown | 2 |
5 files changed, 134 insertions, 29 deletions
diff --git a/bash.html.markdown b/bash.html.markdown index 815290dd..a6bd2b7c 100644 --- a/bash.html.markdown +++ b/bash.html.markdown @@ -21,7 +21,7 @@ Nearly all examples below can be a part of a shell script or executed directly i # As you already figured, comments start with #. Shebang is also a comment. # Simple hello world example: -echo Hello, world! +echo Hello world! # Each command starts on a new line, or after semicolon: echo 'This is the first line'; echo 'This is the second line' @@ -56,24 +56,24 @@ echo "Last program return value: $?" echo "Script's PID: $$" echo "Number of arguments: $#" echo "Scripts arguments: $@" -echo "Scripts arguments separeted in different variables: $1 $2..." +echo "Scripts arguments seperated in different variables: $1 $2..." # Reading a value from input: echo "What's your name?" -read NAME # Note that we didn't need to declare new variable +read NAME # Note that we didn't need to declare a new variable echo Hello, $NAME! # We have the usual if structure: # use 'man test' for more info about conditionals if [ $NAME -ne $USER ] then - echo "Your name is you username" + echo "Your name is your username" else - echo "Your name isn't you username" + echo "Your name isn't your username" fi # There is also conditional execution -echo "Always executed" || echo "Only executed if first command fail" +echo "Always executed" || echo "Only executed if first command fails" echo "Always executed" && echo "Only executed if first command does NOT fail" # Expressions are denoted with the following format: @@ -81,7 +81,7 @@ echo $(( 10 + 5 )) # Unlike other programming languages, bash is a shell — so it works in a context # of current directory. You can list files and directories in the current -# directories with ls command: +# directory with the ls command: ls # These commands have options that control their execution: @@ -89,10 +89,10 @@ ls -l # Lists every file and directory on a separate line # Results of the previous command can be passed to the next command as input. # grep command filters the input with provided patterns. That's how we can list -# txt files in the current directory: +# .txt files in the current directory: ls -l | grep "\.txt" -# You can also redirect a command output, input and error output. +# You can also redirect a command, input and error output. python2 hello.py < "input.in" python2 hello.py > "output.out" python2 hello.py 2> "error.err" @@ -116,7 +116,7 @@ case "$VARIABLE" in *) echo "It is not null.";; esac -# For loops iterate for as many arguments given: +# for loops iterate for as many arguments given: # The contents of var $VARIABLE is printed three times. for VARIABLE in {1..3} do diff --git a/javascript.html.markdown b/javascript.html.markdown index 4584a28c..7fb7ba55 100644 --- a/javascript.html.markdown +++ b/javascript.html.markdown @@ -319,6 +319,37 @@ var myOtherFunc = function(){ myObj.myOtherFunc = myOtherFunc; myObj.myOtherFunc(); // = "HELLO WORLD!" +// We can also specify a context for a function to execute in when we invoke it +// using 'call' or 'apply'. + +var anotherFunc = function(s){ + return this.myString + s; +} +anotherFunc.call(myObj, " And Hello Moon!"); // = "Hello World! And Hello Moon!" + +// The 'apply' function is nearly identical, but takes an array for an argument list. + +anotherFunc.apply(myObj, [" And Hello Sun!"]); // = "Hello World! And Hello Sun!" + +// This is useful when working with a function that accepts a sequence of arguments +// and you want to pass an array. + +Math.min(42, 6, 27); // = 6 +Math.min([42, 6, 27]); // = NaN (uh-oh!) +Math.min.apply(Math, [42, 6, 27]); // = 6 + +// But, 'call' and 'apply' are only temporary. When we want it to stick, we can use +// bind. + +var boundFunc = anotherFunc.bind(myObj); +boundFunc(" And Hello Saturn!"); // = "Hello World! And Hello Saturn!" + +// Bind can also be used to partially apply (curry) a function. + +var product = function(a, b){ return a * b; } +var doubler = product.bind(this, 2); +doubler(8); // = 16 + // When you call a function with the new keyword, a new object is created, and // made available to the function via the this keyword. Functions designed to be // called like that are called constructors. diff --git a/julia.html.markdown b/julia.html.markdown index ce55f956..4b946d46 100644 --- a/julia.html.markdown +++ b/julia.html.markdown @@ -105,7 +105,7 @@ some_var #=> 5 # Accessing a previously unassigned variable is an error try - some_other_var #=> ERROR: some_other_var not defined + some_other_var #=> ERROR: some_other_var not defined catch e println(e) end @@ -417,7 +417,7 @@ try defaults('h') #=> ERROR: no method defaults(Char,) defaults() #=> ERROR: no methods defaults() catch e -println(e) + println(e) end # You can define functions that take keyword arguments @@ -509,7 +509,7 @@ type Tiger end # The default constructor's arguments are the properties -# of the tyep, in order the order they are listed in the definition +# of the type, in the order they are listed in the definition tigger = Tiger(3.5,"orange") #=> Tiger(3.5,"orange") # The type doubles as the constructor function for values of that type diff --git a/objective-c.html.markdown b/objective-c.html.markdown index 1ed0ed58..419c0475 100644 --- a/objective-c.html.markdown +++ b/objective-c.html.markdown @@ -50,52 +50,101 @@ int main (int argc, const char * argv[]) // String NSString *worldString = @"World"; - NSLog(@"Hello %@!", worldString); // Print "Hello World!" + NSLog(@"Hello %@!", worldString); // prints => "Hello World!" + // NSMutableString is a mutable version of the NSString object. + NSMutableString *mutableString = [NSMutableString stringWithString:@"Hello"]; + [mutableString appendString:@" World!"]; + NSLog(@"%@", mutableString); // prints => "Hello World!" // Character literals NSNumber *theLetterZNumber = @'Z'; - char theLetterZ = [theLetterZNumber charValue]; + char theLetterZ = [theLetterZNumber charValue]; // or 'Z' NSLog(@"%c", theLetterZ); // Integral literals NSNumber *fortyTwoNumber = @42; - int fortyTwo = [fortyTwoNumber intValue]; + int fortyTwo = [fortyTwoNumber intValue]; // or 42 NSLog(@"%i", fortyTwo); NSNumber *fortyTwoUnsignedNumber = @42U; - unsigned int fortyTwoUnsigned = [fortyTwoUnsignedNumber unsignedIntValue]; + unsigned int fortyTwoUnsigned = [fortyTwoUnsignedNumber unsignedIntValue]; // or 42 NSLog(@"%u", fortyTwoUnsigned); NSNumber *fortyTwoShortNumber = [NSNumber numberWithShort:42]; - short fortyTwoShort = [fortyTwoShortNumber shortValue]; + short fortyTwoShort = [fortyTwoShortNumber shortValue]; // or 42 NSLog(@"%hi", fortyTwoShort); + + NSNumber *fortyTwoShortNumber = [NSNumber numberWithShort:41]; + unsigned short fortyTwoUnsigned = [fortyTwoShortNumber unsignedShortValue]; // or 41 + NSLog(@"%hu", fortyTwoUnsigned); NSNumber *fortyTwoLongNumber = @42L; - long fortyTwoLong = [fortyTwoLongNumber longValue]; + long fortyTwoLong = [fortyTwoLongNumber longValue]; // or 42 NSLog(@"%li", fortyTwoLong); + NSNumber *fortyTwoLongNumber = @53L; + unsigned long fiftyThreeUnsigned = [fortyTwoLongNumber unsignedLongValue]; // or 53 + NSLog(@"%lu", fiftyThreeUnsigned); + // Floating point literals NSNumber *piFloatNumber = @3.141592654F; - float piFloat = [piFloatNumber floatValue]; - NSLog(@"%f", piFloat); + float piFloat = [piFloatNumber floatValue]; // or 3.141592654f + NSLog(@"%f", piFloat); // prints => 3.141592654 + NSLog(@"%5.2f", piFloat); // prints => " 3.14" NSNumber *piDoubleNumber = @3.1415926535; - double piDouble = [piDoubleNumber doubleValue]; + double piDouble = [piDoubleNumber doubleValue]; // or 3.1415926535 NSLog(@"%f", piDouble); + NSLog(@"%4.2f", piDouble); // prints => "3.14" + + // NSDecimalNumber is a fixed-point class that's more precise then float or double + NSDecimalNumber *oneDecNum = [NSDecimalNumber decimalNumberWithString:@"10.99"]; + NSDecimalNumber *twoDecNum = [NSDecimalNumber decimalNumberWithString:@"5.002"]; + // NSDecimalNumber isn't able to use standard +, -, *, / operators so it provides its own: + [oneDecNum decimalNumberByAdding:twoDecNum]; + [oneDecNum decimalNumberBySubtracting:twoDecNum]; + [oneDecNum decimalNumberByMultiplyingBy:twoDecNum]; + [oneDecNum decimalNumberByDividingBy:twoDecNum]; + NSLog(@"%@", oneDecNum); // prints => 10.99 as NSDecimalNumber is immutable. // BOOL literals NSNumber *yesNumber = @YES; NSNumber *noNumber = @NO; + // or + BOOL yesBool = YES; + BOOL noBool = NO; + NSLog(@"%i", yesBool); // prints => 1 // Array object NSArray *anArray = @[@1, @2, @3, @4]; NSNumber *thirdNumber = anArray[2]; NSLog(@"Third number = %@", thirdNumber); // Print "Third number = 3" + // NSMutableArray is mutable version of NSArray allowing to change items in array + // and extend or shrink array object. Convenient, but not as efficient as NSArray. + NSMutableArray *mutableArray = [NSMutableArray arrayWithCapacity:2]; + [mutableArray addObject:@"Hello"]; + [mutableArray addObject:@"World"]; + [mutableArray removeObjectAtIndex:0]; + NSLog(@"%@", [mutableArray objectAtIndex:0]); // prints => "World" // Dictionary object NSDictionary *aDictionary = @{ @"key1" : @"value1", @"key2" : @"value2" }; NSObject *valueObject = aDictionary[@"A Key"]; NSLog(@"Object = %@", valueObject); // Print "Object = (null)" + // NSMutableDictionary also available as a mutable dictionary object. + NSMutableDictionary *mutableDictionary = [NSMutableDictionary dictionaryWithCapacity:2]; + [mutableDictionary setObject:@"value1" forKey:@"key1"]; + [mutableDictionary setObject:@"value2" forKey:@"key2"]; + [mutableDictionary removeObjectForKey:@"key1"]; + + // Set object + NSSet *set = [NSSet setWithObjects:@"Hello", @"Hello", @"World", nil]; + NSLog(@"%@", set); // prints => {(Hello, World)} (may be in different order) + // NSMutableSet also available as a mutable set object. + NSMutableSet *mutableSet = [NSMutableSet setWithCapacity:2]; + [mutableSet addObject:@"Hello"]; + [mutableSet addObject:@"Hello"]; + NSLog(@"%@", mutableSet); // prints => {(Hello)} /////////////////////////////////////// // Operators @@ -176,6 +225,14 @@ int main (int argc, const char * argv[]) // "2," // "3," + // Object for loop statement. Can be used with any Objective-C object type. + for (id item in values) { + NSLog(@"%@,", item); + } // => prints "0," + // "1," + // "2," + // "3," + // Try-Catch-Finally statements @try { @@ -225,14 +282,30 @@ int main (int argc, const char * argv[]) // @end @interface MyClass : NSObject <MyProtocol> { - int count; - id data; - NSString *name; + // Instance variable declarations (can exist in either interface or implementation file) + int count; // Protected access by default. + @private id data; // Private access. (More convenient to declare in implementation file) + NSString *name; } -// Convenience notation to auto generate public getter and setter +// Convenient notation to auto generate public access getter and setter @property int count; @property (copy) NSString *name; // Copy the object during assignment. @property (readonly) id data; // Declare only a getter method. +// To access public variable in implementation file, use '_' followed by variable name: +_count = 5; +NSLog(@"%d", _count); // prints => 5 +// To access public variable outside implementation file, @property generates setter method +// automatically. Method name is 'set' followed by @property variable name: +MyClass *myClass = [[MyClass alloc] init]; // create MyClass object instance. +[myClass setCount:10]; +NSLog(@"%@", [myClass count]); // prints => 10 +// You can customize the getter and setter names instead of using default 'set' name: +@property (getter=countGet, setter=countSet:) int count; +[myClass countSet:32]; +NSLog(@"%i", [myClass countGet]); // prints => 32 +// For convenience, you may use dot notation to set object instance variables: +myClass.count = 45; +NSLog(@"%i", myClass.count); // prints => 45 // Methods +/- (return type)methodSignature:(Parameter Type *)parameterName; @@ -247,8 +320,9 @@ int main (int argc, const char * argv[]) @end // Implement the methods in an implementation (MyClass.m) file: - -@implementation MyClass +@implementation MyClass { + long count; // Private access instance variable. +} // Call when the object is releasing - (void)dealloc diff --git a/scala.html.markdown b/scala.html.markdown index 03c1ea76..5dfaefe0 100644 --- a/scala.html.markdown +++ b/scala.html.markdown @@ -396,7 +396,7 @@ object Application { // To read a file line by line import scala.io.Source -for(line <- Source.fromPath("myfile.txt").getLines()) +for(line <- Source.fromFile("myfile.txt").getLines()) println(line) // To write a file use Java's PrintWriter |