javascript - 如何强制检查是否已定义变量到读取 True 或 False 的字符串中？

Question

我的控制台日志设置如下:

console.log("getTestStatusActions" + this.userTestStatusActions === undefined);

这给出了单个单词“False”作为输出。

我怎样才能使其输出为:

"getTestStatusActions: userTestStatusActions defined"

或

"getTestStatusActions: userTestStatusActions undefined"

Answer 1

三元!

console.log("getTestStatusActions" + (this.userTestStatusActions === undefined ? "undefined" : "defined"));

或者，为了可读性:

var status = this.userTestStatusActions === undefined ? "undefined" : "defined";
console.log("getTestStatusActions: userTestStatusActions " + status);