index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<ul id="demo"></ul>
<script>
// 传统查找
let str = "app banana orange";
// 如果找到返回下标，如果找不到返回-1
console.log(str.indexOf("xxx"));
// es2015查找
// 如果找到返回true，如果找不到返回false
console.log(str.includes("app"));
// 判断开头是否为指定字符串
console.log(str.startsWith("app"));
// 判断结束是否为指定字符串
console.log(str.endsWith("app"));
// 重复字符串
console.log(str.repeat(10));
// 在字符串开头增加字符串
let str1 = "abc";
let str2 = "def";
console.log(str2.padStart(str1.length + str2.length,str1));
// padends用法同上
</script>
</body>
</html>
运行结果
-1
true
true
false
app banana orangeapp banana orangeapp banana orangeapp banana orangeapp banana orangeapp banana orangeapp banana orangeapp banana orangeapp banana orangeapp banana orange
abcdef
