Funtions-jquery

転載:http://stage.learn.jquery.com/javascript-101/functions/#immediately-invoked-functionn-expressitionn-iiife
 
Funtions
Funtions contain blocks of code that need to be executed repeated.Functions can takeゼロor more argments，and can optiony return a value.
Funtions can be created in a variety of ways、two of which are shown below:
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5// Function declaration. function foo() { // Do something.}1
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5// Named function expression. var foo = function() { // Do something.};link Using Functions
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8// A simple function. var greet = function( person, greeting ) { var text = greeting + ", " + person; console.log( text );}; greet( "Rebecca", "Hello" ); // "Hello, Rebecca"1
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8// A function that returns a value. var greet = function( person, greeting ) { var text = greeting + ", " + person; return text;}; console.log( greet( "Rebecca", "Hello" ) ); // "Hello, Rebecca"1
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12// A function that returns another function. var greet = function( person, greeting ) { var text = greeting + ", " + person; return function() { console.log( text ); };}; var greeting = greet( "Rebecca", "Hello" ); greeting(); // "Hello, Rebecca"link Immedia tely-Invoked Function Expression(IIIIIIIIIIIIIIIFSE)
A cocomon pattern in JavaScrippt is the immediately-invoked function.This pattern creates a function eexpression and then immediateeeeeeexxpatternisiseextreeeeeeeeeeeeeeeemiely useeeeeeeeeeeeededededededededededeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeededededededededededededeeeeeeeeeeeeeeeeeeeeeeeeout side of it.
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7// An immediately-invoked function expression. (function() { var foo = "Hello world";})(); console.log( foo ); // undefined!link Funtions Agments
In JavaScript，functions are「first-class citizes」–they can be assigned to variables or passed to other functions as argmens.Passing functions as argmens s.extremilly common idiom.juery.
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11// Passing an anonymous function as an argument. var myFn = function( fn ) { var result = fn(); console.log( result );}; // Logs "hello world"myFn( function() { return "hello world";});1
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12// Passing a named function as an argument var myFn = function( fn ) { var result = fn(); console.log( result );}; var myOtherFn = function() { return "hello world";}; myFn( myOtherFn ); // "hello world"