我在1月12日发表了《解读ECMAScript[2]——函数、构造器及原型》一文,文中提到了函数声明(Function Declaration)与函数表达式(Function Expression)的概念。在那篇文章中,重点对两者与ECMAScript内置对象Function之间的关系进行了论述,而对两者的区别未加以详细说明。昨天晚上对Web前端颇有研究的jee.chang.sh同学在GTalk上...
JavaScript中Function Declaration与Function Expression 或者说 function fn(){}和var fn=function(){} 的区别 JavaScript是一种解释型语言,函数声明会在JavaScript代码加载后、执行前被解释,而函数表达式只有在执行到这一行代码时才会被解释。 在JS中有两种定义函数的方式, 1是:var aaa=function(){...} 2是:funct...
b) Function Expressions are more versatile. A Function Declaration can only exist as a “statement” in isolation. All it can do is create an object variable parented by its current scope. In contrast, a Function Expression (by definition) is part of a larger construct.If you want to crea...
这叫做函数的声明(Function Declaration)。 (2)函数表达式 除了用function命令声明函数,还可以采用变量赋值的写法。 var print = function(s) { console.log(s); }; 1. 2. 3. 这种写法将一个匿名函数赋值给变量。这时,这个匿名函数又称函数表达式(Function Expression),因为赋值语句的等号右侧只能放表达式。 采用...
function declaration: function fn () {} 1. 2. 3. 4. function expression: var a = function () {}; function () {}; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. --- 切割线:坐着怎么那么热呢 --- 6. 原型链 首先要澄清的一点是,我们通常会使用myfunction...
“Missing name in function declaration.”:“在方法声明中缺少名称”, “Expected an identifier and instead saw ‘{a}’.”:“需要有一个标识符,而不是’{a}’”, “Inner functions should be listed at the top of the outer function.”:“内部函数的声明应该放在此函数的顶部。”, ...
I use function expression where I need a singleton function, or to determine which function to use programmatically (using a named function expression). Some differences between a function declaration and a function expression are: Function expressions allow you to assign different functions to the s...
2. Function expression 2.1 syntax 在一般情况下,我们定义函数prefer function declaration的方式,也就是: functionname(arg1,arg2,...,argN){//body, 如果没有return value, 默认函数return undefined.} 可以看到function declaration的code是statement, 包含在代码块中常常看到的花括号{},现在我们提出一种新的函数...
The parameterfunctioninworkis declared to be a pointer to a function taking oneintargument and returning alongvalue. The parentheses around the parameter name are required; without them, the declaration would specify a function returning a pointer to alongvalue. ...
You cannot self-invoke a function declaration. You have to add parentheses around the function to indicate that it is a function expression: Example (function() { letx ="Hello!!";// I will invoke myself })(); Try it Yourself » ...