Function: isNil()

function isNil(value): value is null | undefined;

Checks if a value is null or undefined. 检查值是否为null或undefined。

Parameters

Parameter	Type	Description
value	unknown	The value to check / 要检查的值

Returns

value is null | undefined

True if the value is null or undefined / 如果值是null或undefined则返回true

Example

isNil(null) // => true
isNil(undefined) // => true
isNil(void 0) // => true (void 0 is undefined)
isNil('') // => false
isNil(0) // => false
isNil(false) // => false
isNil([]) // => false
isNil({}) // => false
isNil(NaN) // => false

// Useful for optional chaining checks
const obj = { a: null, b: undefined, c: 'value' }
Object.keys(obj).filter(key => !isNil(obj[key])) // => ['c']

Since

1.0.0