190819-utils
Version:
尚硅谷大前端自定义工具函数库
38 lines (34 loc) • 767 B
HTML
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>测试各种遍历对象的效率</title>
</head>
<body>
<script>
/*
测试: for...in / keys & forEach
耗时: 差不多
*/
const obj = new Object();
for (let i = 0; i < 100000; i++) {
obj[i] = 1
}
// for..in
console.time()
for (const key in obj) {
if (obj.hasOwnProperty(key)) {
// const element = obj[key];
}
}
console.timeEnd()
// keys() + forEach
console.time()
Object.keys(obj).forEach(key => {
// let element32 = obj[key]
})
console.timeEnd()
</script>
</body>
</html>