还有其他的方式来调用函数。常见的一些情形是某些地方需要动态调用函数,或者函数的实参数量是变化的,或者调用函数的上下文需要指定为在运行时确定的特定对象。 显然,函数本身就是对象,因此这些对象也有方法(参见 Function 对象)。call() 和apply() 方法可用于实现这些目的。
这个匿名函数的参数在执行时会通过判断exports和define是否存在,来确定当前执行环境: 当前环境为CommonJS/Node.js时,匿名函数的参数就是一个手动定义的define函数 当前环境为AMD/RequireJS时,匿名函数的参数就直接是AMD中的define函数。 如此,在保证了define方法的存在后,匿名函数内部就可以直接使用define函数来创建模块。
we’ll call the function and place the username as theargument. The argument is the actual value that gets passed into the function, in this case it is the string"Sammy".
Imagine we have a bookkeeping object that keeps all the function call results of longRunningFunction like this:var longRunningFnBookKeeper = { 2 : 3, 4 : 5 . . . } The longRunningFnBookKeeper is a simple JavaScript object, which is going to hold all the input (as keys) and outputs (a...
// Define an object with some properties and a method // We will later pass the method as a callback function to another function var clientData = { id: 094545, fullName: "Not Set", // setUserName is a method on the clientData object setUserName: function (firstName, lastName) { ...
.NET isn't required to read the result of a JavaScript (JS) call. JS functions return void(0)/void 0 or undefined.Provide a displayTickerAlert1 JS function. The function is called with InvokeVoidAsync and doesn't return a value:
// Define the original function.var checkNumericRange = function (value) { if (typeof value !== 'number') return false; else return value >= this.minimum && value <= this.maximum;}// The range object will become the this value in the callback function.var range = { minimum: 10, ...
})//加载模块require(['myModule'],function(my){ my.printName(); }) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 语法: AMD标准中,定义了下面两个API: 1.require([module], callback) 2. define(id, [depends], callback) ...
test('reflect-metadata',()=>{constkey='myKey'// 🔴 装饰器语法@Reflect.metadata(key,'inClass')classFoo{@Reflect.metadata(key,'inStaticMember')staticstaticMember=1@Reflect.metadata(key,'inMember')member=2}// 🔴 上述装饰器等价于Reflect.defineMetadata(key,'inClass',Foo)Reflect.defineMetadata...
//The item is a callback function $("#btn_1").click(function() { alert("Btn 1 Clicked"); }); As you see in the preceding example, we pass a function as a parameter to theclickmethod. And the click method will call (or execute) the callback function we passed to it. This exa...