JS about accurate calculation and numerical formatting as well as direct indexing JS file _javascript skills

Copy Code code as follows:

(function () {
var calc = {
/*
function, addition function, used to get the exact addition result
Description: JavaScript addition results will be error, in two floating-point number added when it is more obvious. This function returns a more precise addition result.
Parameters: Arg1: The first addends; arg2 the number of decimal places to keep (you can not pass this parameter, if not the number of decimal places)
Call: Calc.add (ARG1,ARG2,D)
Return value: The result of adding two numbers
*/
Add:function (Arg1, arg2,d) {
Arg1 = Arg1.tostring (), arg2 = Arg2.tostring ();
var Arg1arr = Arg1.split ("."), Arg2arr = Arg2.split ("."), D1 = Arg1arr.length = 2? ARG1ARR[1]: "", d2 = Arg2arr.length = = 2? ARG2ARR[1]: "";
var maxlen = Math.max (D1.length, d2.length);
var m = Math.pow (MaxLen);
var result = number ((ARG1 * m + arg2 * m)/m). ToFixed (MaxLen));
var d = arguments[2];
return typeof D = = "Number"? Number (Result). ToFixed (d)): result;
},
/*
Function: Subtraction function, used to get exact subtraction results
Description: The function returns a more accurate subtraction result.
Parameters: Arg1: The first addends; arg2 the number of decimal places to keep (this parameter can not be passed and the number of decimal places is not processed if not passed)
Call: Calc.sub (ARG1,ARG2)
Return value: The result of subtracting two numbers
*/
Sub:function (Arg1, arg2) {
Return Calc.add (Arg1,-number (ARG2), arguments[2]);
},
/*
Function: multiplication function, used to get accurate result of multiplication
Description: The function returns more accurate multiplication results.
Parameters: Arg1: First multiplier; arg2 second multiplier; d to keep the number of decimal places (you can not pass this parameter, if not the number of decimal digits)
Call: Calc.mul (ARG1,ARG2)
Return value: The result of multiplying two numbers
*/
Mul:function (Arg1, arg2) {
var r1 = arg1.tostring (), r2 = Arg2.tostring (), M, resultval, d = arguments[2];
m = (R1.split (".") [1]? R1.split (".") [1].length:0) + (R2.split (".") [1]? R2.split (".") [1].length:0);
Resultval = number (R1.replace (".", "")) * Number (R2.replace (".", ""))/Math.pow (M);
Return typeof D!== "number"? Number (Resultval): Number (resultval.tofixed (parseint (d)));
},
/*
Function: Division function, used to get exact division results
Description: The function returns a more precise division result.
Parameters: arg1: divisor; arg2 divisor; d The number of decimal places to keep (you can not pass this argument, if not the number of decimal places)
Call: Calc.div (ARG1,ARG2)
Return value: Arg1 In addition to ARG2 results
*/
Div:function (Arg1, arg2) {
var r1 = arg1.tostring (), r2 = Arg2.tostring (), M, resultval, d = arguments[2];
m = (R2.split (".") [1]? R2.split (".") [1].length:0)-(R1.split (".") [1]? R1.split (".") [1].length:0);
Resultval = number (R1.replace (".", ""))/Number (R2.replace (".", "")) * MATH.POW (M);
Return typeof D!== "number"? Number (Resultval): Number (resultval.tofixed (parseint (d)));
},
/*
The values are rounded and formatted.
@param num Value (number or string)
@param number of decimal places to keep cent
@param whether the Isthousand need to be 0: not required, 1: required (numerical type);
A string @return format, such as ' 1,234,567.45 '
@type String
Call: Calc.formatnumber (Num,cent,isthousand)
*/
Formatnumber:function FormatNumber (Num,cent,isthousand) {
num = num.tostring (). Replace (/\$|\,/g, "");
if (isNaN (num))//check that the incoming value is a numeric type.
num = "0";
if (isNaN (cent))//ensures that incoming decimal places are numeric values.
cent = 0;
cent = parseint (cent);
cent = math.abs (cent);//Find the number of decimal places to ensure a positive integer.
if (isNaN (Isthousand))//ensures that the thousand-bit value type is required for incoming.
Isthousand = 0;
Isthousand = parseint (Isthousand);
if (Isthousand < 0)
Isthousand = 0;
if (Isthousand >=1)//Ensure that the number passed in is only 0 or 1
Isthousand = 1;
Sign = (num = (num = math.abs (num));/get symbol (positive/negative)
Math.floor: Returns the largest integer less than or equal to its numeric argument
num = Math.floor (Num*math.pow (10,cent) +0.50000000001);//converts the specified decimal places to integers. Extra decimal places rounded.
cents = Num%math.pow (10,cent); Find the decimal digit value.
num = Math.floor (Num/math.pow (10,cent)). toString ();//Find an integer digit value.
cents = cents.tostring ();//converts decimal places to strings to find decimal lengths.
while (cents.length<cent) {//complements the decimal places to the specified number of digits.
cents = "0" + cents;
}
if (Isthousand = = 0)//no thousand characters are required.
Return (((sign)? ': '-') + num + '. ' + cents);
The integer portion is formatted as a decimal point.
for (var i = 0; I < Math.floor ((num.length-(1+i))/3); i++)
num = num.substring (0,num.length-(4*i+3)) + ', ' +
Num.substring (num.length-(4*i+3));
Return (((sign)? ': '-') + num + '. ' + cents);
}
};
Window. Calc = calc;
}());