JS-如果可以同时满足多个条件，则哪个条件可以运行? [英] JS - If multiple conditions can be true at the same time, which one runs?

问题描述

如果多个if语句可以同时为真，那么JS如何确定要运行哪个语句?在下面的示例中，我知道很酷，现在我对自己有很多墨西哥玉米片."将被退回，但我只是想知道如何确定?如果不是 friendsAtYourParty === 0 ，而是 friendsAtYourParty<怎么办?3 (很酷，现在我对自己有很多墨西哥玉米片."会再次返回，但是为什么呢?).我在想，也许是更具体/更接近胜利"价值的那个?

If multiple if-statements can be true at the same time, how does JS determine which one to run? In the example below, I know "Cool, now I have a lot of nachos to myself." will get returned, but I just wonder how that is determined? What if instead of friendsAtYourParty === 0 it would be friendsAtYourParty < 3 ("Cool, now I have a lot of nachos to myself." would get returned again, but why?). I was thinking maybe the one that is more specific/closer to the value "wins"?

if (friendsAtYourParty === 0) {
  console.log("Cool, now I have a lot of nachos to myself.");
} else if (friendsAtYourParty < 4) {
  console.log("Perfect amount to play some Mario Kart.");
} else {
  console.log("Wooooo turn on the dance music!");
}

推荐答案

当您拥有 if/else 链 only 时，第一个 if 将执行匹配的条件.毕竟，这就是 if/else 的工作方式:

When you have an if/else chain only the first if condition that matches would be executed. After all, that's how if/else works:

if (condition) {
  //only executed when condition is true
} else {
  //only executed when condition is false 
}

当条件为 true 时， else 部分将不会执行.如果您有多个 if/else

The else part will NOT execute when the condition is true. Nothing changes when you have more than one if/else:

if (condition1) {
  //only executed when condition1 is true
} else if (condition2) {
  //only executed when condition2 is true and condition1 is false
} else {
 //only executed when both condition1 and condition2 are false
}

if/else 链描述了以下逻辑流程，因此为什么总是对其进行可预测的评估:

An if/else chain describes the following logic flow, hence why it will always be evaluated predictably:

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