李振良-KubernetesK8s CKA 认证实战班

示例三

let arr = []for( let i = 0; i < 3; i++ ){    arr[ i ] = function(){        console.log( this )    }}let fn = arr[ 0 ]arr[ 0 ]fn()

上述中的 this 会打印出什么呢？

arr[ 0 ] ==> arr 对象{ 0: fn, 1: fn, 2: fn } ==> arr.0 ==> arr.0.call( this ) ==> this === arrfn() ==> fn.call( undefined ) ==> this === undefined == 浏览器转化 ==> window