Object.fromEntries
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Object.fromEntries</title>
</head>
<body>
<script>
// Object.fromEntries：把二维数组转为对象
// Object.entries：将把对象转为二维数组，ES8
// 二维数组
const result = Object.fromEntries([
['name', '哈哈'],
['job', 'Java, 大数据, 前端, 云计算']
]);
console.log(result) // {name: "哈哈", job: "Java, 大数据, 前端, 云计算"}
// Map
const m = new Map();
m.set('name', 'haha');
const result2 = Object.fromEntries(m);
console.log(result2) // {name: "haha"}
const arr = Object.entries({
name: "哈哈"
})
console.log(arr); //
console.log(arr[0], arr[0][0], arr[0][1]); // ["name", "哈哈"] "name" "哈哈"
</script>
</body>
</html>
trimStart 和 trimEnd
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>trimStart 与 trimEnd</title>
</head>
<body>
<script>
// trim
let str = ' i love you ';
console.log(str);
console.log(str.trim())
console.log(str.trimStart());
console.log(str.trimEnd());
</script>
</body>
</html>