Implementing sprintf and printf functions in JavaScript_javascript skills

Implement the sprintf / printf functions found in most languages ​​​​under JavaScript.

http://www.webtoolkit.info/javascript-sprintf.html: A relatively complete simulation of the sprintf function. Available formatting wildcards:
1.%% - Returns the percent sign itself
2.%b - Binary number
3.%c - ASCII corresponding character
4.%d - integer
5.%f - floating point number
6.%o - Octal number
7.%s - string
8.%x - hexadecimal number (lowercase letter form)
9.%X - hexadecimal number (uppercase letter form)

Available options between % signs and wildcard characters include (e.g. %.2f):

1. (Force to display the and - sign in front of the number as a sign of positive and negative numbers. By default, only negative numbers display the - sign)
2.- (variables left aligned)
3.0 (use 0 as right-aligned padding character)
4.[0-9] (Set the minimum width of the variable)
5..[0-9] (Set floating point precision or string length)

Copy code The code is as follows:

/**
*
*  Javascript sprintf
*  http://www.webtoolkit.info/
*
*
**/

sprintfWrapper = {

  init : function () {

    if (typeof arguments == "undefined") { return null; }
    if (arguments.length < 1) { return null; }
    if (typeof arguments[0] != "string") { return null; }
    if (typeof RegExp == "undefined") { return null; }

    var string = arguments[0];
    var exp = new RegExp(/(%([%]|(-)?( |x20)?(0)?(d )?(.(d)?)?([bcdfosxX])))/g);
    var matches = new Array();
    var strings = new Array();
    var convCount = 0;
    var stringPosStart = 0;
    var stringPosEnd = 0;
    var matchPosEnd = 0;
    var newString = '';
    var match = null;

    while (match = exp.exec(string)) {
      if (match[9]) { convCount = 1; }

      stringPosStart = matchPosEnd;
      stringPosEnd = exp.lastIndex - match[0].length;
      strings[strings.length] = string.substring(stringPosStart, stringPosEnd);

      matchPosEnd = exp.lastIndex;
      matches[matches.length] = {
        match: match[0],
        left: match[3] ? true : false,
        sign: match[4] || '',
        pad: match[5] || ' ',
        min: match[6] || 0,
        precision: match[8],
        code: match[9] || '%',
        negative: parseInt(arguments[convCount]) < 0 ? true : false,
        argument: String(arguments[convCount])
      };
    }
    strings[strings.length] = string.substring(matchPosEnd);

    if (matches.length == 0) { return string; }
    if ((arguments.length - 1) < convCount) { return null; }

    var code = null;
    var match = null;
    var i = null;

    for (i=0; i

      if (matches[i].code == '%') { substitution = '%' }
      else if (matches[i].code == 'b') {
        matches[i].argument = String(Math.abs(parseInt(matches[i].argument)).toString(2));
        substitution = sprintfWrapper.convert(matches[i], true);
      }
      else if (matches[i].code == 'c') {
        matches[i].argument = String(String.fromCharCode(parseInt(Math.abs(parseInt(matches[i].argument)))));
        substitution = sprintfWrapper.convert(matches[i], true);
      }
      else if (matches[i].code == 'd') {
        matches[i].argument = String(Math.abs(parseInt(matches[i].argument)));
        substitution = sprintfWrapper.convert(matches[i]);
      }
      else if (matches[i].code == 'f') {
        matches[i].argument = String(Math.abs(parseFloat(matches[i].argument)).toFixed(matches[i].precision ? matches[i].precision : 6));
        substitution = sprintfWrapper.convert(matches[i]);
      }
      else if (matches[i].code == 'o') {
        matches[i].argument = String(Math.abs(parseInt(matches[i].argument)).toString(8));
        substitution = sprintfWrapper.convert(matches[i]);
      }
      else if (matches[i].code == 's') {
        matches[i].argument = matches[i].argument.substring(0, matches[i].precision ? matches[i].precision : matches[i].argument.length)
        substitution = sprintfWrapper.convert(matches[i], true);
      }
      else if (matches[i].code == 'x') {
        matches[i].argument = String(Math.abs(parseInt(matches[i].argument)).toString(16));
        substitution = sprintfWrapper.convert(matches[i]);
      }
      else if (matches[i].code == 'X') {
        matches[i].argument = String(Math.abs(parseInt(matches[i].argument)).toString(16));
        substitution = sprintfWrapper.convert(matches[i]).toUpperCase();
      }
      else {
        substitution = matches[i].match;
      }

      newString = strings[i];
      newString = substitution;

    }
    newString = strings[i];

    return newString;

  },

  convert : function(match, nosign){
    if (nosign) {
      match.sign = '';
    } else {
      match.sign = match.negative ? '-' : match.sign;
    }
    var l = match.min - match.argument.length 1 - match.sign.length;
    var pad = new Array(l < 0 ? 0 : l).join(match.pad);
    if (!match.left) {
      if (match.pad == "0" || nosign) {
        return match.sign pad match.argument;
      } else {
        return pad match.sign match.argument;
      }
    } else {
      if (match.pad == "0" || nosign) {
        return match.sign match.argument pad.replace(/0/g, ' ');
      } else {
        return match.sign match.argument pad;
      }
    }
  }
}

sprintf = sprintfWrapper.init;

If you just want to simply replace the content of the position variable without additional formatting, you can use the printf provided in the relatively simple YUI tools:

Copy code The code is as follows:

YAHOO.Tools.printf = function() {
var num = arguments.length;
var oStr = arguments[0];
for (var i = 1; i < num; i ) {
var pattern = "\{" (i-1) "\}";
var re = new RegExp(pattern, "g");
oStr = oStr.replace(re, arguments[i]);
}
return oStr;
}

When used like YAHOO.Tools.printf("Display string {0}, {1}.", "1", "2"); use {?} to match.