function test(arg){ // 1. 形参 arg 是 "hi" // 2. 因为函数声明比变量声明优先级高，所以此时 arg 是 function console.log(arg); var arg = 'hello'; // 3.var arg 变量声明被忽略， arg = 'hello'被执行 function arg(){console.log('hello world') } console.log(ar...
You can use the function directly, as a variable value: lettext ="The temperature is "+ toCelsius(77) +" Celsius"; Try it Yourself » You will learn a lot more about functions later in this tutorial. Local Variables Variables declared within a JavaScript function, becomeLOCALto the funct...
functionadd(x, y){returnx + y; }// 将函数赋值给一个变量varoperator=add;// 将函数作为参数和返回值functiona(op){returnop; } a(add)(1,1)// 2 函数名的提升 JavaScript 引擎将函数名视同变量名,所以采用function命令声明函数时,整个函数会像变量声明一样,被提升到代码头部。所以,下面的代码不会报...
functionadd(x, y){returnx + y; }// 将函数赋值给一个变量 varoperator = add; // 将函数作为参数和返回值 functiona(op){returnop; } a(add)(1,1)// 2 1.5、函数名的提升 JavaScript 引擎将函数名视同变量名,所以采用function命令声明函数时,整个函数会...
function foo2() { return { bar:'hello' } } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. //第一个返回一个对象 //第二个返回undefine 因为第二个 return 后面没内容,分号自动加载 return 后面 3.4 void的使用 javascript:void(0) 该操作符指定要计算一个表达式但是不返回值。
In the second case, the function did not alter the object that was passed; instead, it created a new local variable that happens to have the same name as the global object passed in, so there is no effect on the global object that was passed in. ...
A Function Expression (abbreviated form is FE) is a function which: 函数表达式(简写FE)是这样的一个函数 in the source code can only be defined at the expression position; can have an optional name; it’s definition has no effect on variable object; ...
从Javascript对function的定义, function是一个由代码集合而成的对象. 从中我们可看出,我们可以使用向C语言中的函数那样使用function,也可以对function进行面向对象编程.当然Javascript中function的强 大还不止如此. 2. 如何使用function 2.1定义 复制 functionmyfunc(param) {//code} ...
function myFunction() { var localVar = "Hello"; globalVar = localVar; } myFunction(); console.log(globalVar); // 输出:"Hello" // 方法2:使用闭包 function myFunction() { var localVar = "Hello"; return function() { return localVar; ...
// 全局作用域varglobalVariable="I am a global variable";functionfoo(){// 函数内部作用域varlocalVariable="I am a local variable";console.log(localVariable);// 输出:I am a local variableconsole.log(globalVariable);// 输出:I am a global variable}foo();console.log(globalVariable);// 输出...