You can test if a function exists in Javascript by simply testing for the name of it in an if() conditional. One thing to be aware of is that you can’t test for the function name by itself (well you can, but if it doesn’t exist the Javascript will error out); it’s a method...
当 require() 函数加载test模块时,就会先加载 math.js 模块。 // dataService.js define(['math'],function(math){functiondoSomething(){letresult = math.add(2,9);console.log(result);}return{doSomething};}); 设置一个主模块,统一调度当前...
functiontest(){varfs =require("fs");//Create the databasevardb =newSQL.Database();//NOTE:You can also use new sql.Database(data) where// data is an Uint8Array representing an SQLite database file// Execute some sqlsqlstr ="CREATE TABLE hello (a int, b char);"; sqlstr +="INS...
beforeEach(function() { console.log('before every test in every file'); }); # Delayed Root Suite If you need to perform asynchronous operations before any of your suites are run, you may delay the root suite. Run mocha with the --delay flag. This will attach a special callback funct...
catch this filecount in javascript function. loop usingWhy are you counting through the files to check if a file exists? What would happen if the file server contained thousands of images?IMO it would be better to search for one image....
You can test if an object exists by testing if the type isundefined: Example: if(typeofmyObj ==="undefined") Try it Yourself » But you cannot test if an object isnull, because this will throw an error if the object isundefined: ...
consttest={name:'1+1=10',func:function(){returnthis.name;},};console.log(test.func());// 1+1=10consttest2={name:'1+1=2',};test2.func=test.func;console.log(test2.func());// 1+1=2 在函数内部,this的值取决于函数如何被调用。同一个函数,根据其调用的方式,this的值是不同的...
plugins.length; i++) { if (navigator.plugins[i].name.indexOf(pluginname) >= 0) { f = navigator.plugins[i].description.split(pluginname)[1]; return f; break; } } } return false; } function wrapParamAndStart(requestParam) { start(JSON.stringify(requestParam)); } /** * 前端抓取...
//1. unit under test describe('Products Service', function() { describe('Add new product', function() { //2. scenario and 3. expectation it('When no price is specified, then the product status is pending approval', ()=> { const newProduct = new ProductService().add(...); expect...
createDirIfNotExists('test'); 3.currentURL:返回当前链接url const currentURL = () => window.location.href; currentURL(); // 'https://juejin.im' 4.distance:返回两点间的距离 该代码段通过计算欧几里得距离来返回两点之间的距离。 const distance = (x0, y0, x1, y1) => Math.hypot(x1 - x0...