JSFiddle - React, Tailwind, and code Playground

JavaScript

// 循环
var a = new Array(100).fill(1)
var start = new Date().getTime()
for (var i = 0; i < 100000; i++){
	a[0]
}
console.log('循环索引', new Date().getTime() - start)

var start = new Date().getTime()
for (var i = 0; i < 100000; i++) {
	a.slice(0,1)
}
console.log('循环slice', new Date().getTime() - start)