Javascript 的自用基本函数汇总

//=================================== javascript ===================================

//---- 自定义函数, 函数应该放在闭包外面, 放在闭包里面掉用不了 -----------

//substr(start[,length])表示从start位置开始取length个字符串
//substring(start,end)表示从start，到end之间的字符串，包括start位置的字符但是不包括end位置的字符
//1.start不一定就是第一个参数，end也不一定就是第二个参数，substring(3,1)时，开始位置是1，结束位置是3；
//2.当要返回的子字符串是从开始位置到结束时，end的值必须大于等于字符串的长度，
//如上边的str.substring(7,8)，按照索引从0开始算的话end的最大值为7，但这边却用8，当然，使用大于8的数返回的结果也是一样的，这点比较有意思。

function dec_hex(i)
{
   var s = "0123456789ABCDEF";
   var ss = s.substr(i/16,1) + s.substr(i%16,1); //获取子字符串

   return(ss);
}

function hex_dec(s)
{
    var arg = [0,1,2,3,4,5,6,7,8,9,0,0,0,0,0,0,0,10,11,12,13,14,15];        //数组

    s = s.toUpperCase(s);
    var pos1 = s.charCodeAt(0) - 48;        //取字符串的ASCII
    var pos2 = s.charCodeAt(1) - 48;        //'A'的ASCII为65, -48=17, 即arg[17]=10
    var Rtn = arg[pos1]*16 + arg[pos2];

    return(Rtn);
}

function GetCRC8(p, Num)        //p为数组传递参数, Num为数据的长度
{
 var crcarray = [
        0, 94,188,226, 97, 63,221,131,194,156,126, 32,163,253, 31, 65,
      157,195, 33,127,252,162, 64, 30, 95, 1,227,189, 62, 96,130,220,
       35,125,159,193, 66, 28,254,160,225,191, 93, 3,128,222, 60, 98,
      190,224, 2, 92,223,129, 99, 61,124, 34,192,158, 29, 67,161,255,
       70, 24,250,164, 39,121,155,197,132,218, 56,102,229,187, 89, 7,
      219,133,103, 57,186,228, 6, 88, 25, 71,165,251,120, 38,196,154,
      101, 59,217,135, 4, 90,184,230,167,249, 27, 69,198,152,122, 36,
      248,166, 68, 26,153,199, 37,123, 58,100,134,216, 91, 5,231,185,
      140,210, 48,110,237,179, 81, 15, 78, 16,242,172, 47,113,147,205,
       17, 79,173,243,112, 46,204,146,211,141,111, 49,178,236, 14, 80,
      175,241, 19, 77,206,144,114, 44,109, 51,209,143, 12, 82,176,238,
       50,108,142,208, 83, 13,239,177,240,174, 76, 18,145,207, 45,115,
      202,148,118, 40,171,245, 23, 73, 8, 86,180,234,105, 55,213,139,
       87, 9,235,181, 54,104,138,212,149,203, 41,119,244,170, 72, 22,
      233,183, 85, 11,136,214, 52,106, 43,117,151,201, 74, 20,246,168,
      116, 42,200,150, 21, 75,169,247,182,232, 10, 84,215,137,107, 53];
 var temp,CRC8 = 0;

 for(var i=0; i<Num; i++)
        CRC8 = crcarray[CRC8 ^ p[i]];

 return(CRC8);
}

var calCRC16 = function(strSrc)
{
    //strSrc = "010200C40016";
    var len = strSrc.length;
    var reg_crc = 0xffff;
    var m_Crc;
    for(var i=0 ;i <len/2;i++)
    {
        var c = strSrc.substr(2*i,2);
        var r = parseInt(c,16);
        reg_crc ^= r;
        for(var j=0;j<8;j++)
        {
            m_Crc = reg_crc;
            reg_crc>>=1;
            if(m_Crc&0x0001)
            {
                reg_crc ^= 0xa001;
            }
        }

    }
    var temp = reg_crc.toString(16);
    return (temp.substr(2,2)+temp.substr(0,2)).toUpperCase();
}

function DateToString(datetime)
{
 var year = datetime.getFullYear();
 var month = datetime.getMonth()+1;        //js从0开始取
 var date1 = datetime.getDate();
 var hour = datetime.getHours();
 var minutes = datetime.getMinutes();
 var second = datetime.getSeconds();

 if(month < 10){
   month = "0" + month;
 }
 if(date1 < 10){
   date1 = "0" + date1;
 }
 if(hour < 10){
   hour = "0" + hour;
 }
 if(minutes <10){
   minutes = "0" + minutes;
 }
 if(second <10){
   second = "0" + second;
 }

 year = year.toString();
 //year = year.substring(2, 4);
 year = year.substr(2,2);
 var time = year + month + date1 + hour + minutes + second;    //第1个变量为string,则整个变量为string????

 return(time);
}

//dateObj是一个日期对象，days表示给这个日期加多少天，比如说4，5（天）
function dateAdd(dateObj,days)
{
  var tempDate = dateObj.valueOf();
  tempDate = tempDate + days * 24 * 60 * 60 * 1000;
  tempDate = new Date(tempDate);
  return tempDate;
}

function Trim(str){
 if(str.charAt(0) == " "){
  str = str.slice(1);
  str = Trim(str);
 }
 return str;
}

//判断是否是空
function isEmpty(pObj,errMsg){
 var obj = eval(pObj);
 if( obj == null || Trim(obj.value) == ""){
  if (errMsg == null || errMsg =="")
   alert("输入为空!");
  else
   alert(errMsg);
  obj.focus();
  return false;
 }
 return true;
}

//判断是否是数字
function isNumber(pObj,errMsg){
 var obj = eval(pObj);
 strRef = "1234567890";
 if(!isEmpty(pObj,errMsg))return false;
 for (i=0;i<obj.value.length;i++) {
  tempChar= obj.value.substring(i,i+1);
  if (strRef.indexOf(tempChar,0)==-1) {
   if (errMsg == null || errMsg =="")
    alert("数据不符合要求,请检查");
   else
    alert(errMsg);
   if(obj.type=="text")
    obj.focus();
   return false;
  }
 }
 return true;
}

function isIE()
{
    if (window.navigator.userAgent.toLowerCase().indexOf("msie") >= 1)
        return true;
    else
        return false;
}

// 返回两数之间随机数的函数
function rand(a, b){
    return Math.round(a + Math.random()*(b - a));
}

// 定义名为each的函数，方便遍历数组或者对象的处理
function each(o, f){
    if(o.length == undefined) {
        for(var n in o)             //for...in语句
            f.call(o[n], n, o[n]);
    }else{
        for(var i=0, l = o.length; i<l; i++)
            f.call(o[i], i, o[i]);
    }
}

Array.prototype.each = function(callback)
{
    for (i=0; i<this.length; i++) {
       callback.call(this, this[i]);
    }
}
var arrayObject = ["JavaScript","Prototype","Jquery"];
arrayObject.each(function(x){alert(x)});
//用prototype方法给JavaScrip的数组对象Array加一个方法each，each方法传入一个回调函数callback，
//callback内部根据当前调用数组对象长度循环执行callback方法，callback方法在执行时内部this就指当前调用，
//并传入一个参数this[i]为数组当前索引对象。上面代码运行时会顺序看到弹出对话框显示"JavaScript","Prototype","Jquery"。

//
//转成人民币大写金额形式
function RMBUpper(num)
{
  var strOutput = "";
  var strUnit = '仟佰拾亿仟佰拾万仟佰拾元角分';
  num += "00";
  var intPos = num.indexOf('.');
  if (intPos >= 0)
    num = num.substring(0, intPos) + num.substr(intPos + 1, 2);
  strUnit = strUnit.substr(strUnit.length - num.length);
  for (var i=0; i < num.length; i++)
    strOutput += '零壹贰叁肆伍陆柒捌玖'.substr(num.substr(i,1),1) + strUnit.substr(i,1);

  return strOutput.replace(/零角零分$/, '整').replace(/零[仟佰拾]/g, '零').replace(/零{2,}/g, '零').replace(/零([亿|万])/g, '$1').replace(/零+元/, '元').replace(/亿零{0,3}万/, '亿').replace(/^元/, "零元");
};

function cmycurd(num)
{
  var str1 = '零壹贰叁肆伍陆柒捌玖'; //0-9所对应的汉字
  var str2 = '万仟佰拾亿仟佰拾万仟佰拾元角分'; //数字位所对应的汉字
  var str3; //从原num值中取出的值
  var str4; //数字的字符串形式
  var str5 = ''; //人民币大写金额形式
  var i; //循环变量
  var j; //num的值乘以100的字符串长度
  var ch1; //数字的汉语读法
  var ch2; //数字位的汉字读法
  var nzero = 0; //用来计算连续的零值是几个

  num = Math.abs(num).toFixed(2); //将num取绝对值并四舍五入取2位小数
  str4 = (num * 100).toFixed(0).toString(); //将num乘100并转换成字符串形式
  j = str4.length; //找出最高位
  if (j > 15){return '溢出';}
  str2 = str2.substr(15-j); //取出对应位数的str2的值。如：200.55,j为5所以str2=佰拾元角分

  //循环取出每一位需要转换的值
  for(i=0;i<j;i++){
    str3 = str4.substr(i,1); //取出需转换的某一位的值
    if (i != (j-3) && i != (j-7) && i != (j-11) && i != (j-15)){ //当所取位数不为元、万、亿、万亿上的数字时
    if (str3 == '0'){
      ch1 = '';
      ch2 = '';
      nzero = nzero + 1;
    }
    else{
      if(str3 != '0' && nzero != 0){
        ch1 = '零' + str1.substr(str3*1,1);
        ch2 = str2.substr(i,1);
        nzero = 0;
      }
      else{
        ch1 = str1.substr(str3*1,1);
        ch2 = str2.substr(i,1);
        nzero = 0;
      }
    }
   }
   else{ //该位是万亿，亿，万，元位等关键位
      if (str3 != '0' && nzero != 0){
        ch1 = "零" + str1.substr(str3*1,1);
        ch2 = str2.substr(i,1);
        nzero = 0;
      }
      else{
     if (str3 != '0' && nzero == 0){
          ch1 = str1.substr(str3*1,1);
          ch2 = str2.substr(i,1);
          nzero = 0;
      }
        else{
    if (str3 == '0' && nzero >= 3){
            ch1 = '';
            ch2 = '';
            nzero = nzero + 1;
       }
       else{
      if (j >= 11){
              ch1 = '';
              nzero = nzero + 1;
   }
   else{
     ch1 = '';
     ch2 = str2.substr(i,1);
     nzero = nzero + 1;
   }
          }
  }
   }
 }
    if (i == (j-11) || i == (j-3)){ //如果该位是亿位或元位，则必须写上
        ch2 = str2.substr(i,1);
    }
    str5 = str5 + ch1 + ch2;

    if (i == j-1 && str3 == '0' ){ //最后一位（分）为0时，加上“整”
      str5 = str5 + '整';
    }
  }
  if (num == 0){
    str5 = '零元整';
  }
  return str5;
}

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