JavaScript sprintf

Return a formatted string

function sprintf ( ) { // Return a formatted string // // version: 909.322 // discuss at: http://phpjs.org/functions/sprintf // + original by: Ash Searle (http://hexmen.com/blog/) // + namespaced by: Michael White (http://getsprink.com) // + tweaked by: Jack // + improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net) // + input by: Paulo Ricardo F. Santos // + improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net) // + input by: Brett Zamir (http://brett-zamir.me) // + improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net) // * example 1: sprintf("%01.2f", 123.1); // * returns 1: 123.10 // * example 2: sprintf("[%10s]", 'monkey'); // * returns 2: '[ monkey]' // * example 3: sprintf("[%'#10s]", 'monkey'); // * returns 3: '[####monkey]' 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) { if (!chr) {chr = ' ';} 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, customPadChar) { var diff = minWidth - value.length; if (diff > 0) { if (leftJustify || !zeroPad) { value = pad(value, minWidth, customPadChar, 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, customPadChar) { if (precision != null) { value = value.slice(0, precision); } return justify(value, '', leftJustify, minWidth, zeroPad, customPadChar); }; // doFormat() var doFormat = function (substring, valueIndex, flags, minWidth, _, precision, type) { var number; var prefix; var method; var textTransform; var value; if (substring == '%%') {return '%';} // parse flags var leftJustify = false, positivePrefix = '', zeroPad = false, prefixBaseX = false, customPadChar = ' '; var flagsl = flags.length; for (var j = 0; flags && j < flagsl; j++) { switch (flags.charAt(j)) { case ' ': positivePrefix = ' '; break; case '+': positivePrefix = '+'; break; case '-': leftJustify = true; break; case "'": customPadChar = flags.charAt(j+1); 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 : undefined; } 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? value = valueIndex ? a[valueIndex.slice(0, -1)] : a[i++]; switch (type) { case 's': return formatString(String(value), leftJustify, minWidth, precision, zeroPad, customPadChar); 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': number = parseInt(+value, 10); 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': number = +value; prefix = number < 0 ? '-' : positivePrefix; method = ['toExponential', 'toFixed', 'toPrecision']['efg'.indexOf(type.toLowerCase())]; 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);}

external links: original PHP docs | raw js source

Examples

» Example 1

Running

1

sprintf("%01.2f", 123.1);

 

Should return

1

123.10

 

 

» Example 2

Running

1

sprintf("[%10s]", 'monkey');

 

Should return

1

'[    monkey]'

 

 

Dependencies

No dependencies, you can use this function standalone.

 

 

下载代码:

http://download.csdn.net/source/1972080

http://d.namipan.com/d/ef8fc4b6a0ec4e761878b197441564c876bec24284320000

 

原文链接: http://phpjs.org/functions/sprintf:522