Add an integer to the thousand symbol in JavaScript

If num is an integer, convert it to a string with a thousands symbol:

Number (num). toString (). Replace (/(\d) (? = (\d{3}) + (?! \d))/g, ' $ ' + ', ');

In addition, Http://www.cnblogs.com/yeminglong/p/5301295.html gives the conversion format of decimals, as follows:

1 /**2 *3 * @param num4 * @param Precision5 * @param separator6 * @returns {*}7 *=======================================================8 * FormatNumber (10000) = "Up"9 * FormatNumber (10000, 2) = "10,000.00"Ten * FormatNumber (10000.123456, 2) = "10,000.12" One * FormatNumber (10000.123456, 2, ') = "Ten 000.12" A * FormatNumber (. 123456, 2, ') = "0.12" - * FormatNumber (2, ") =" 56.00 " - * FormatNumber (0, ") =" " the * FormatNumber (' 56. ') = "The " - * FormatNumber (' 56.a ') =nan - *======================================================= - */ + functionformatnumber (num, precision, separator) { -  　　 varparts; +  　　 //determine whether a number A  　　 if(!isnan (parsefloat (num)) &&isfinite (num)) { at  　　　　 //Convert similar. 5, 5. Data into 0.5, 5, for data precision processing, and why -  　　　　 //Do not write directly if in judgment (!isnan (num = parsefloat (num)) && isfinite (num)) -  　　　　 //is because parsefloat has a strange precision problem, such as parsefloat (12312312.1234567119) -  　　　　 //the value becomes 12312312.123456713. -num =Number (num); -  　　　　 //processing the number of decimal places innum = (typeofPrecision!== ' undefined '?num.tofixed (precision): num). toString (); -  　　　　 //separating the fractional and integer parts of a number toParts = Num.split ('. ')); +  　　 //integer part plus [separator] delimited, borrowing a well-known regular expression -Parts[0] = parts[0].tostring (). Replace (/(\d) (? = (\d{3}) + (?! \d)/g, ' $ ' + (separator | | ‘,‘)); the  *  　　　　 returnParts.join ('. ')); $ }Panax Notoginseng  　　 returnNaN; -}

1 /**2 * Convert numbers to currency format3 * @param decimals4 * @param dec_point5 * @param thousands_sep6 * @returns {string}7 */8number.prototype.format=function(decimals, Dec_point, thousands_sep) {9 varnum = ( This+ ')Ten. replace (/[^0-9+\-ee.) /g, "); One varn =!isfinite (+num)? 0: +num, APrec =!isfinite (+decimals)? 0: Math.Abs (decimals), -Sep = (typeofThousands_sep = = = ' undefined ')? ‘,‘: Thousands_sep, -Dec = (typeofDec_point = = = ' undefined ')? ‘.‘: Dec_point, thes = ', -Tofixedfix =function(n, prec) { - varK = Math.pow (10, prec); - return' + (Math.Round (n * k)/k) + . toFixed (PREC); - }; + //Fix for IE parsefloat (0.55). toFixed (0) = 0; As = (prec? tofixedfix (N, prec): ' +Math.Round (n)) at. Split ('. ')); - if(S[0].length > 3) { -S[0] = S[0].replace (/\b (? = (?: \ D{3}) + (?! \d))/g, Sep); - } - if((S[1] | | ‘‘) -. length <prec) { inS[1] = S[1] | | ‘‘; -S[1] + =NewArray (prec-s[1].length + 1) to. Join (' 0 '); + } - returnS.join (DEC); the}

Add an integer to the thousand symbol in JavaScript