JZTXT

js中的false

发布时间 2023-11-24 15:25:13作者: 伪装大牛

js中有五个false的值

  console.log(Boolean(false))
    console.log(Boolean(undefined))
    console.log(Boolean(""))
    console.log(Boolean(0))
    console.log(Boolean(null))

其余均为true 如下边几个都为true

console.log(Boolean("false"))
console.log(Boolean("null"))
console.log(Boolean(-1))
console.log(Boolean({}))

 所以判断数组长度不为0 就可以用

if(arr.length)