JavaScript performs operations on large Numbers

For very large or very small Numbers, floating point values can be expressed using scientific notation. Using scientific notation, a number can be expressed as a number plus e/ e, followed by multiplying by a multiple of 10, such as:

var num1 = 3.125e7; // 31250000 var num2 = 3e-17; // 0.00000000000000003

For the addition and subtraction of extremely large Numbers, the method of string + scientific notation can be used, such as:

//We only consider the case of large integers, not the decimal function strAdd(sNum1, sNum2){

  

  var sNum1 = ['0', sNum1].join(''), sNum2 = ['0', sNum2].join(''); 

   

  var len1 = sNum1.length, len2 = sNum2.length, 

    zeroArr = function(len){ 

      var arr = new Array(len), i=len; 

      while(i--){arr[i] = 0;} 

      return arr; 

    }; 

   if(len1 > len2){ 

    var arrTemp = zeroArr(len1 - len2); 

    arrTemp.push(sNum2), 

    sNum2 = arrTemp.join(''); 

  } 

  else if(len2 > len1){ 

    var arrTemp = zeroArr(len2 - len1); 

    arrTemp.push(sNum1), 

    sNum1 = arrTemp.join(''); 

  } 

    

  var arr1 = sNum1.split(''), arr2 = sNum2.split(''); 

   var arrAddRes = new Array(arr1.length), i=arr1.length; 

   var andone = 0, //Whether the low spots add to the one & cake;       Cur1, cur2 curAdd; < br / >
   while(i--){ 

    cur1 = +arr1[i], cur2 = +arr2[i]; 

    curAdd = cur1+cur2+andone; 

    if(10 > curAdd) 

      arrAddRes[i] = curAdd, 

      andone = 0; 

    else

      arrAddRes[i] = +curAdd.toString().slice(1,2), 

      andone = 1; 

  } 

   if(!andone){ //If not, intercept the previous 0& PI;       ArrAddRes. Splice (0, 1); < br / >
  } 

    

  var keeplen = 19; // js Only the decimal point after the decimal point 18 position    var eAfter = arrAddRes.length - 1; // e The next multiple    var eBefore, eBeforeStr = '';      // e The decimal part in front  

  if(keeplen < arrAddRes.length) 

    eBeforeStr = [arrAddRes[0], '.', arrAddRes.slice(1, keeplen).join('')].join(''); 

  else

    eBeforeStr = [arrAddRes[0], '.', arrAddRes.slice(1).join('')].join(''); 

   eBefore = +eBeforeStr; 

   return [Number(arrAddRes.join('')), eBefore, eAfter]; 

} 

 strAdd('1234567890', '9876543210'); // -> [1111111100, 1.1111111, 9]

The code is as above, isn't it also very simple.