使用 if 语句设置 javascript 变量——“var = x"应该在 IF 内部还是外部? [英] setting a javascript variable with an if statement -- should the 'var = x' be inside or outside the IF?

问题描述

这可能是一个基本问题，但我很难找到答案.

This may be a basic question but I'm having difficulty finding an answer.

您想根据 var A 设置 var B

You want to set var B based on var A

你愿意吗

var B = if(A == "red"){"hot"}else{"cool"}

我认为这行不通.

我想你可以做到

if(A == "red"){var B = "hot"}else{var B = "cool"}

这看起来不是特别优雅.我的意思是，为了清楚起见，我更喜欢以 var b = .... 开头的内容.

This doesn't seem particularly elegant. I mean I would prefer something that starts with var b = .... just for clarity's sake.

推荐答案

完美使用三元组

var B = (A ==="red") ? "hot":"cool";

如果为真，三元表达式将始终返回第一个值，否则返回第二个值.非常适合一次性 if/else 语句，但如果您遇到更多嵌套条件，请务必使用传统的 if/else 块以提高可读性.

Ternary expressions will always return the first value if true, the second value if not. Great for one-off if/else statements, but if you get into more nested conditions, be sure to use the traditional if/else blocks for readability.

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