JavaScript实现把十进制非负整数转换为二进制

程序员文章站 2024-03-18 21:46:28

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<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">    
    <title>IFE ECMAScript</title>
</head>
<body>        
    <input id="dec-number" type="number" placeholder="输入一个十进制非负整数">
    <button id="trans-btn">转化为二进制</button>
    <p id="result">运算结果</p>
    <script>

        function dec2bin(decNumber) {
            try {
                if (decNumber < 0) {
                    throw "必须为非负整数";
                }
            } catch (error) {          
                return "Error:" + error;
            }
            var temp = 0;
            var num = decNumber;
            var arr = new Array();
            while (num > 0) {
                temp = num % 2;
                arr.push(temp);
                num = parseInt(num / 2);
            }
            return arr.reverse().join("");
        }
        
        var btn = document.querySelector("#trans-btn");
        btn.addEventListener("click", function () {
            var aaa = document.getElementById("dec-number").value;
            var res = document.getElementById("result");
            res.innerHTML = dec2bin(aaa);
        });
    </script>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">    
    <title>IFE ECMAScript</title>
</head>
<body>        
    <input id="dec-number" type="number" placeholder="输入一个十进制非负整数">
    <input id="bin-bit" type="number" placeholder="输入转化后二进制数字位数">
    <button id="trans-btn">转化为二进制</button>
    <p id="result">运算结果</p>
    <script>

        function dec2bin(decNumber, binBit) {
            try {
                if (decNumber < 0) {
                    throw "必须为非负整数";
                }
            } catch (error) {          
                return "Error:" + error;
            }
            var temp = 0;
            var num = decNumber;
            var arr = new Array();
            while (num > 0) {
                temp = num % 2;
                arr.push(temp);
                num = parseInt(num / 2);
            }
            var str = arr.reverse().join("");
            var len = str.length;
            if (len > binBit) {
                console.warn("输入的二进制数字位数太小，按原本的位数显示！");
                return str;
            }
            else {
                for (var i = 0; i < binBit-len; i++) {  //注意str.length是动态变化的
                    str = "0" + str;
                }
                return str;
            }
        }
       
        var btn = document.querySelector("#trans-btn");
        btn.addEventListener("click", function () {
            var aaa = document.getElementById("dec-number").value;
            var binbit = document.getElementById("bin-bit").value;
            var res = document.getElementById("result");
            res.innerHTML = dec2bin(aaa, binbit);
        });

    </script>
</body>
</html>