Several programming languages implement a sprintf function, to output a formatted string. It originated from the C programming language, printf function. Its a string manipulation function.
This is limited sprintf Javascript implementation. Function returns a string formatted by the usual printf conventions. See below for more details. You must specify the string and how to format the variables in it. Possible format values:
%% - Returns a percent sign
%b - Binary number
%c - The character according to the ASCII value
%d - Signed decimal number
%f - Floating-point number
%o - Octal number
%s - String
%x - Hexadecimal number (lowercase letters)
%X - Hexadecimal number (uppercase letters)
Additional format values. These are placed between the % and the letter (example %.2f):
+ (Forces both + and - in front of numbers. By default, only negative numbers are marked)
- (Left-justifies the variable value)
0 zero will be used for padding the results to the right string size
[0-9] (Specifies the minimum width held of to the variable value)
.[0-9] (Specifies the number of decimal digits or maximum string length)
If you plan using UTF-8 encoding in your project don't forget to set the page encoding to UTF-8 (Content-Type meta tag), and use Javascript UTF-8 utility found on this website.
/**
*
* 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<matches.length; 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;
