JS写的CRC16校验算法

var CRC = {};

CRC.CRC16 = function (data) {
    var len = data.length;
    if (len > 0) {
        var crc = 0xFFFF;

        for (var i = 0; i < len; i++) {
            crc = (crc ^ (data[i]));
            for (var j = 0; j < 8; j++) {
                crc = (crc & 1) != 0 ? ((crc >> 1) ^ 0xA001) : (crc >> 1);
            }
        }
        var hi = ((crc & 0xFF00) >> 8);  //高位置
        var lo = (crc & 0x00FF);         //低位置

        return [hi, lo];
    }
    return [0, 0];
};

CRC.isArray = function (arr) {
    return Object.prototype.toString.call(arr) === '[object Array]';
};

CRC.ToCRC16 = function (str, isReverse) {
    return CRC.toString(CRC.CRC16(CRC.isArray(str) ? str : CRC.strToByte(str)), isReverse);
};

CRC.ToModbusCRC16 = function (str, isReverse) {
    return CRC.toString(CRC.CRC16(CRC.isArray(str) ? str : CRC.strToHex(str)), isReverse);
};

CRC.strToByte = function (str) {
    var tmp = str.split(''), arr = [];
    for (var i = 0, c = tmp.length; i < c; i++) {
        var j = encodeURI(tmp[i]);
        if (j.length == 1) {
            arr.push(j.charCodeAt());
        } else {
            var b = j.split('%');
            for (var m = 1; m < b.length; m++) {
                arr.push(parseInt('0x' + b[m]));
            }
        }
    }
    return arr;
};

CRC.convertChinese = function (str) {
    var tmp = str.split(''), arr = [];
    for (var i = 0, c = tmp.length; i < c; i++) {
        var s = tmp[i].charCodeAt();
        if (s <= 0 || s >= 127) {
            arr.push(s.toString(16));
        }
        else {
            arr.push(tmp[i]);
        }
    }
    return arr;
};

CRC.filterChinese = function (str) {
    var tmp = str.split(''), arr = [];
    for (var i = 0, c = tmp.length; i < c; i++) {
        var s = tmp[i].charCodeAt();
        if (s > 0 && s < 127) {
            arr.push(tmp[i]);
        }
    }
    return arr;
};

CRC.strToHex = function (hex, isFilterChinese) {
    hex = isFilterChinese ? CRC.filterChinese(hex).join('') : CRC.convertChinese(hex).join('');

    //清除所有空格
    hex = hex.replace(/\s/g, "");
    //若字符个数为奇数，补一个0
    hex += hex.length % 2 != 0 ? "0" : "";

    var c = hex.length / 2, arr = [];
    for (var i = 0; i < c; i++) {
        arr.push(parseInt(hex.substr(i * 2, 2), 16));
    }
    return arr;
};

CRC.padLeft = function (s, w, pc) {
    if (pc == undefined) {
        pc = '0';
    }
    for (var i = 0, c = w - s.length; i < c; i++) {
        s = pc + s;
    }
    return s;
};

CRC.toString = function (arr, isReverse) {
    if (typeof isReverse == 'undefined') {
        isReverse = true;
    }
    var hi = arr[0], lo = arr[1];
    return CRC.padLeft((isReverse ? hi + lo * 0x100 : hi * 0x100 + lo).toString(16).toUpperCase(), 4, '0');
};

示例：

console.log(CRC.ToCRC16('12345678', true));
console.log(CRC.ToCRC16('12345678', false));

console.log(CRC.ToModbusCRC16('12345678', true));

console.log(CRC.ToCRC16('你好，我们测试一下CRC16算法', true));

计算结果：