In this article we show how to use the with statement in JavaScript. The with statement extends the scope chain for a statement. The with statementThe with statement extends the scope chain for a block. It allows you to access properties of an object without repeating the object reference. ...
with(expression)statement expression将给定的表达式添加到在评估语句时使用的作用域链上。表达式周围的括号是必需的。statement任何语句。要执行多个语句,请使用一个块语句 ({ ... })对这些语句进行分组。 描述 JavaScript查找某个未使用命名空间的变量时,会通过作用域链来查找,作用域链是跟执行代码的context或者包含...
An Empirical Study on the Rewritability of the with Statement in JavaScriptChanghee ParkHongki LeeSukyoung Ryu
浏览器兼容性 js vara,x,y;varr=10;with(Math){a=PI*r*r;x=r*cos(PI);y=r*sin(PI/2);} 规范 Specification ECMAScript® 2026 Language Specification #sec-with-statement
The purpose of establishing a binding is to copy data between the two objects involved: the source from where the data comes and the destination to which the data goes. You might think that you can accomplish this goal using a simple assignment statement: ...
In this article we show how to use predicates in JavaScript. A predicate in general meaning is a statement about something that is either true or false. In programming, predicates represent single argument functions that return a boolean value. JS predicate with find...
Working of labeled break statement in JavaScript As you can see in the image above, theouterlooplabel identifies the outer loop. Whenbreak outerloop;is encountered, it exits the outer loop, and control shifts to the statements following it. ...
In your JavaScript file, add a call to console.log after the if statement, but inside the event listener. After you make this change, your complete JavaScript code should look like this. JavaScript Copy 'use strict'; const switcher = document.querySelector('.btn'); switcher.addEventListener...
JavaScript Array JS Multidimensional Array JavaScript String JavaScript for...in loop JavaScript Number JavaScript Symbol Exceptions and Modules JavaScript try...catch...finally JavaScript throw Statement JavaScript Modules JS ES6 JavaScript ES6 JavaScript Arrow Function JavaScript Default Parameters JavaScript ...
代码语言:javascript 代码运行次数:0 运行 AI代码解释 """IOBase also supports the:keyword:`with`statement.Inthisexample,fp is closed after the suiteofthewithstatement is complete:withopen('spam.txt','r')asfp:fp.write('Spam and eggs!')""" ...