console 命令行工具 X clear
console
<!DOCTYPE html> 
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <script>
        m=prompt("请输入菱形行数：");
        var n=Number(m)
        if (n%2 ==0){
            alert("请输入奇数！")
        }else{

            for(var i=1;i<=n;i++){
                if(i<=(n+1)/2){
                    for (var j=1;j<=(n+1)/2-i;j++){
                        document.write("-");
                    }
                    for (var k=0;k<2*i-1;k++){
                        document.write("*");
                    }
                }else{
                    for(var j=1;j<=i-(n+1)/2;j++){
                        document.write("-");
                    }
                    for(var k=2*(n-i)+1;k>0;k--){
                        document.write("*")
                    }
                }
                document.write("<br/>")
            }
        } 
    </script>
</head>
<body>
</body>
</html>