JavaScript简写三元运算符 [英] JavaScript shorthand ternary operator

问题描述

我知道在PHP 5.3中，而不是使用这种冗余的三元运算符语法：

I know that in PHP 5.3 instead of using this redundant ternary operator syntax:

startingNum = startingNum ? startingNum : 1

...我们可以在适用的情况下为三元运算符使用简写语法：

...we can use a shorthand syntax for our ternary operators where applicable:

startingNum = startingNum ?: 1

我知道JavaScript中的三元运算符：

And I know about the ternary operator in JavaScript:

startingNum = startingNum ? startingNum : 1

...但是有速记吗？

...but is there a shorthand?

推荐答案

var startingNumber = startingNumber || 1;

类似您要查找的内容，如果未定义则默认为默认值？

Something like that what you're looking for, where it defaults if undefined?

var foo = bar || 1; // 1
var bar = 2;
foo = bar || 1;     // 2

顺便说一下，这适用于很多场景，包括对象：

By the way, this works for a lot of scenarios, including objects:

var foo = bar || {}; // secure an object is assigned when bar is absent

这篇关于JavaScript简写三元运算符的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！