If statement 2 returns true, the loop will start over again, if it returns false, the loop will end.If you omit statement 2, you must provide a break inside the loop. Otherwise the loop will never end. This will crash your browser. Read about breaks in a later chapter of this ...
For/Of and For/In Loops Thefor/inloop and thefor/ofloop are explained in the next chapter. While Loops Thewhileloop and thedo/whileare explained in the next chapters. Exercise? Consider the following code: let i, x = ''; for (i = 0; i <= 5; i++) { ...
letkey;constarr = [];arr[0] = “a”;arr[100] = “b”;arr[10000] = “c”;for(keyinarr) {if(arr.hasOwnProperty(key) &&/⁰$|^[1–9]\d*$/.test(key) &&key <=4294967294) {console.log(arr[key]);}} For-in 仅遍历现有实体。上例中f...
for-in 循环遍历的是对象的属性,而不是数组的索引。因此, for-in 遍历的对象不局限于数组,还可以遍历对象。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 constperson={fname:"san",lname:"zhang",age:29};letinfo;for(infoinperson){console.log("person["+info+"] = "+person[info]);}// ...
In this chapter, we start off by exploring all the nitty gritty details of the for loop, followed by those of while in the next chapter. Let's begin. What is for meant for? So what is for meant for? Well, precisely speaking: The for loop is meant to repeatedly execute a piece of...
JavaScript for loop JavaScript for...in loop JavaScript for...of loop Thefor...ofloop was introduced in the later versions ofJavaScript ES6. Thefor..ofloop in JavaScript allows you to iterate over iterable objects (arrays, sets, maps, strings etc). ...
In the second iteration, thekeyvariable is assigned the next key ofobject. The body of the loop is then executed. This process continues until there are no more keys over which to iterate. Note: Once you get the keys of an object, you can easily find their corresponding values. ...
(示例中跳到第8行)后,仍然输出“退出” 2.return跳 记录exit...和return的用法 1.exit用来跳出循环 Oracle代码: declare V_KBP varchar2(10); begin loop IF V_KBP IS NULL THEN EXIT;...END IF; end loop; dbms_output.put_line(‘退出’); end; exit跳出循环(示例中跳到第8行)后,仍然输出“...
大家好,前面已经介绍过循环结构的for..next和do...loop系列语句。还有一种用于处理对象集合的循环语句,即for each...next语句,在本节介绍。(下面程序控制结构图帮助回顾) For each...next语句是在集合的对象中循环,对集合中满足某种条件的对象或所有对象执行操作。
for...in for...in语句以任意顺序迭代一个对象的除Symbol以外的可枚举属性，包括继承的可枚举属性。语...