09_函数参数的默认值设置.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>函数参数默认值</title>
</head>
<body>
    <script>
        // ES6 允许给函数参数赋初始值
        
        // 1. 形参初始值 具有默认值的参数一般位置要靠后（潜规则）
        function add (a, b, c = 10) {
            return a + b + c
        }
        let result = add(1, 2)
        console.log(result)

        // 2. 可以与解构赋值结合
        function connect ({host = "127.0.0.1", username, password, port}) {
            console.log(host)
            console.log(username)
            console.log(password)
            console.log(port)
        }
        connect({
            host: 'localhost',
            username: 'root',
            password: 'root',
            port: 3306
        })
    </script>
</body>
</html>