模拟一下console对象的assert方法:即传入的参数不是正确的表达式,就抛出错误。 1console.log('---');2functionassert(expression,message){3if(!expression){4throw{name:'Assert function',meaage:message};5}6}7assert(100,'error shows 1');//此时没出错8assert(undefined,'error shows 2');//此时出错 ...
1//method 1: function命令2functiontest(){3console.log('hello function');4}56//method 2:函数表达式,赋值给变量7vartest1=function(){//这是个匿名函数8console.log('hello function1');9};//注意这里有分号1011//method 3:Function构造函数12vartest2=newFunction(13'return "hello function2"'14);15...
How do I use the onShowFileSelector() function to start Gallery to upload images? What should I do if a white screen is displayed or the page cannot be displayed when the Web component loads a page? What are the differences between javaScriptProxy and registerJavaScriptProxy? How many ...
对于 thisArg，如果 thisArg 参数有值，则每次 callback 函数被调用的时候，this 都会指向 thisArg 参数上的这个对象。如果省略了 thisArg 参数,或者赋值为 null 或 undefined，则 this 指向全局对象 。需要记住的是，map函数不会改变原有数组的值。实例：var array1 = [1, 4, 9, 16];// pass a function t...
How do I use the onShowFileSelector() function to start Gallery to upload images? What should I do if a white screen is displayed or the page cannot be displayed when the Web component loads a page? What are the differences between javaScriptProxy and registerJavaScriptProxy? How many ...
function getComplement(color) { switch (color) { case COLOR_RED: return COLOR_GREEN; case COLOR_GREEN: return COLOR_RED; default: throw new Error('Undefined color'); } } 实例:消除魔术字符串 魔术字符串指的是,在代码之中多次出现、与代码形成强耦合的某一个具体的字符串或者数值。风格良好的代码...
ActionLink from a JavaScript function? how do i change the url without redirecting How do I clear my input field after an AJAX call? How do i clear off teh validations in MVC? How do I conditionally Display a Div? How do I create and return a simple text file? How do I create ...
allow one dot or comma to be enter in javascript function Allow only Numbers(0-9) Or a-z, A-Z along with backspace , space in textbox Allow only one dot in a text box using javascript - client side allow user to multi select dropdownlist options Allowing only Alphanumeric characters a...
functiondisplay(){console.log(this);// 'this' 只想全局对象 object}display(); This is a normal function call. In this case, the value of this in the display() method is eitherwindowor the global object in non-strict mode. In strict mode, the value of this is undefined. ...
undefined:'use strict'; function fun() { return this; } console.assert(fun() === undefined); console.assert(fun.call(2) === 2); console.assert(fun.apply(null) === null); console.assert(fun.call(undefined) === undefined); console.assert(fun.bind(true)() === true); ...