JS之形参带默认值的写法代码

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    <meta charset="UTF-8">
    <title>JS之形参带默认值的写法代码</title>
</head>
<body>
<script>
    function c(x, y){
        //console.log(y);   //结果：undefined或者值
        if(y == undefined){
            y = 3; //如果调用函数时，没有传递第二个参数y的值，那么让y=3
        }
        console.log(x + y); //结果：5 6
    }
    c(2);
    c(2, 4);
</script>
</body>
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