JavaScript：如何测试一个变量是否不为NULL
问题描述：
我的理解是下面的两行JavaScript是等价的，但我很困惑这是最好的做法使用：
My understanding is the two JavaScript lines below are equivalent but I'm confused which is the best practice to use:
我应该：
if (myVar) {...}
或
if (myVar !== null) {...}
答
如果 myVar 是 truthy ，则第一个将执行 if 如果 myVar 是除了 true $ c> $ c> null 。
They are not equivalent. The first will execute the block following the if statement if myVar is truthy (i.e. evaluates to true in a conditional), while the second will execute the block if myVar is any value other than null.
JavaScript中唯一不真实的值是以下（aka falsy ）：
The only values that are not truthy in JavaScript are the following (a.k.a. falsy values):
-
null - code> undefined
-
0 - code>（空字符串）
-
false -
NaN
nullundefined0-
""(the empty string) falseNaN