javascript:
function sprintf( ) {
// Return a formatted string
//
// + original by: Ash Searle (http://hexmen.com/blog/)
// + namespaced by: Michael White (http://crestidg.com)
var regex = /%%|%(\d+\$)?([-+#0 ]*)(\*\d+\$|\*|\d+)?(\.(\*\d+\$|\*|\d+))?([scboxXuidfegEG])/g;
var a = arguments, i = 0, format = a[i++];
// pad()
var pad = function(str, len, chr, leftJustify) {
var padding = (str.length >= len) ? '' : Array(1 + len - str.length >>> 0).join(chr);
return leftJustify ? str + padding : padding + str;
};
// justify()
var justify = function(value, prefix, leftJustify, minWidth, zeroPad) {
var diff = minWidth - value.length;
if (diff > 0) {
if (leftJustify || !zeroPad) {
value = pad(value, minWidth, ' ', leftJustify);
} else {
value = value.slice(0, prefix.length) + pad('', diff, '0', true) + value.slice(prefix.length);
}
}
return value;
};
// formatBaseX()
var formatBaseX = function(value, base, prefix, leftJustify, minWidth, precision, zeroPad) {
// Note: casts negative numbers to positive ones
var number = value >>> 0;
prefix = prefix && number && {'2': '0b', '8': '0', '16': '0x'}[base] || '';
value = prefix + pad(number.toString(base), precision || 0, '0', false);
return justify(value, prefix, leftJustify, minWidth, zeroPad);
};
// formatString()
var formatString = function(value, leftJustify, minWidth, precision, zeroPad) {
if (precision != null) {
value = value.slice(0, precision);
}
return justify(value, '', leftJustify, minWidth, zeroPad);
};
// finalFormat()
var doFormat = function(substring, valueIndex, flags, minWidth, _, precision, type) {
if (substring == '%%') return '%';
// parse flags
var leftJustify = false, positivePrefix = '', zeroPad = false, prefixBaseX = false;
for (var j = 0; flags && j < flags.length; j++) switch (flags.charAt(j)) {
case ' ': positivePrefix = ' '; break;
case '+': positivePrefix = '+'; break;
case '-': leftJustify = true; break;
case '0': zeroPad = true; break;
case '#': prefixBaseX = true; break;
}
// parameters may be null, undefined, empty-string or real valued
// we want to ignore null, undefined and empty-string values
if (!minWidth) {
minWidth = 0;
} else if (minWidth == '*') {
minWidth = +a[i++];
} else if (minWidth.charAt(0) == '*') {
minWidth = +a[minWidth.slice(1, -1)];
} else {
minWidth = +minWidth;
}
// Note: undocumented perl feature:
if (minWidth < 0) {
minWidth = -minWidth;
leftJustify = true;
}
if (!isFinite(minWidth)) {
throw new Error('sprintf: (minimum-)width must be finite');
}
if (!precision) {
precision = 'fFeE'.indexOf(type) > -1 ? 6 : (type == 'd') ? 0 : void(0);
} else if (precision == '*') {
precision = +a[i++];
} else if (precision.charAt(0) == '*') {
precision = +a[precision.slice(1, -1)];
} else {
precision = +precision;
}
// grab value using valueIndex if required?
var value = valueIndex ? a[valueIndex.slice(0, -1)] : a[i++];
switch (type) {
case 's': return formatString(String(value), leftJustify, minWidth, precision, zeroPad);
case 'c': return formatString(String.fromCharCode(+value), leftJustify, minWidth, precision, zeroPad);
case 'b': return formatBaseX(value, 2, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
case 'o': return formatBaseX(value, 8, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
case 'x': return formatBaseX(value, 16, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
case 'X': return formatBaseX(value, 16, prefixBaseX, leftJustify, minWidth, precision, zeroPad).toUpperCase();
case 'u': return formatBaseX(value, 10, prefixBaseX, leftJustify, minWidth, precision, zeroPad);
case 'i':
case 'd': {
var number = parseInt(+value);
var prefix = number < 0 ? '-' : positivePrefix;
value = prefix + pad(String(Math.abs(number)), precision, '0', false);
return justify(value, prefix, leftJustify, minWidth, zeroPad);
}
case 'e':
case 'E':
case 'f':
case 'F':
case 'g':
case 'G':
{
var number = +value;
var prefix = number < 0 ? '-' : positivePrefix;
var method = ['toExponential', 'toFixed', 'toPrecision']['efg'.indexOf(type.toLowerCase())];
var textTransform = ['toString', 'toUpperCase']['eEfFgG'.indexOf(type) % 2];
value = prefix + Math.abs(number)[method](precision);
return justify(value, prefix, leftJustify, minWidth, zeroPad)[textTransform]();
}
default: return substring;
}
};
return format.replace(regex, doFormat);
}
//Примеры:
sprintf("%01.2f", 123.1);
// 123.10