JS案例——判断质数

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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>质数练习</title>
</head>
<body>
    <script>
        function isPrime(num){
            if(num === 0 || num === 1){
                return false
            }
            if(num === 2){
                return true
            }
            
            for(let i = num - 1;i > 1;i--){
                if(num % i === 0){
                    return false
                }
                
            }
            return true
        }
        let num = +prompt('请输入您想判断的数字')
        let ans = isPrime(num)
        if(ans){
            document.write(`${num}是质数`)
        }
        else{
            document.write(`${num}不是质数`)
        }
    </script>
</body>
</html>
posted @ 2026-02-23 23:42  AttaSayyid  阅读(11)  评论(0)    收藏  举报