30秒学会 JavaScript 片段 – isNil

Returns true if the specified value is null or undefined, false otherwise.

Use the strict equality operator to check if the value of val is equal to null or undefined.

代码片段

const isNil = val => val === undefined || val === null;

使用样例

isNil(null); // true
isNil(undefined); // true
isNil(''); // false