JavaScript中有sprintf等價物嗎？

Question

如果是這樣，它是什麼？

我不介意它是否涉及使用外部庫。

Answer 1

Here（broken - Alternative location @ Google Code）是一個實現了功能的jQuery插件。

_{Original page mirror在Wayback機器上。}

插件代碼爲also at the mirror：

/*############################################################################## 
# ____________________________________________________________________ 
# /                 \ 
# |    ____ __  ___   _____/ ___ ___  | 
# |  ____  /\/ \ '/ \ //  /__ / \/ \ | 
# | /_ \ //////___/ \__ / /____/// | 
# | /|_//////// / \/ / /____/  | 
# | \____/ // \/_/ /\__/ _____/ \__/ \___//   | 
# |              /   | 
# |                  | 
# | Copyright (c) 2007        MindStep SCOP SARL | 
# | Herve Masson              | 
# |                  | 
# |  www.mindstep.com        www.mjslib.com | 
# | info-oss@mindstep.com       mjslib@mjslib.com | 
# \____________________________________________________________________/ 
# 
# Version: 1.0.0 
# 
# (Svn version: $Id: jquery.printf.js 3434 2007-08-27 09:31:20Z herve $) 
# 
#----------[This product is distributed under a BSD license]----------------- 
# 
# Redistribution and use in source and binary forms, with or without 
# modification, are permitted provided that the following conditions 
# are met: 
# 
#  1. Redistributions of source code must retain the above copyright 
#  notice, this list of conditions and the following disclaimer. 
# 
#  2. Redistributions in binary form must reproduce the above copyright 
#  notice, this list of conditions and the following disclaimer in 
#  the documentation and/or other materials provided with the 
#  distribution. 
# 
# THIS SOFTWARE IS PROVIDED BY THE MINDSTEP CORP PROJECT ``AS IS'' AND 
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MINDSTEP CORP OR CONTRIBUTORS 
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
# 
# The views and conclusions contained in the software and documentation 
# are those of the authors and should not be interpreted as representing 
# official policies, either expressed or implied, of MindStep Corp. 
# 
################################################################################ 
# 
# This is a jQuery [jquery.com] plugin that implements printf' like functions 
# (Examples and documentation at: http://mjslib.com) 
# 
# @author: Herve Masson 
# @version: 1.0.0 (8/27/2007) 
# @requires jQuery v1.1.2 or later 
# 
# (Based on the legacy mjslib.org framework) 
# 
##############################################################################*/ 

(function($) { 

    /* 
    ** Just an equivalent of the corresponding libc function 
    ** 
    ** var str=jQuery.sprintf("%010d %-10s",intvalue,strvalue); 
    ** 
    */ 

    $.sprintf=function(fmt) 
    { 
     return _sprintf_(fmt,arguments,1); 
    } 


    /* 
    ** vsprintf takes an argument list instead of a list of arguments (duh!) 
    ** (useful when forwarding parameters from one of your functions to a printf call) 
    ** 
    ** str=jQuery.vsprintf(parameters[,offset]); 
    ** 
    **  The 'offset' value, when present, instructs vprintf to start at the 
    **  corresponding index in the parameter list instead, of 0 
    ** 
    ** Example 1: 
    ** 
    **  function myprintf(<printf like arguments>) 
    **  { 
    **   var str=jQuery.vsprintf(arguments); 
    **   .. 
    **  } 
    **  myprintf("illegal value : %s",somevalue); 
    ** 
    ** 
    ** Example 2: 
    ** 
    **  function logit(level,<the rest is printf like arguments>) 
    **  { 
    **   var str=jQuery.vsprintf(arguments,1); // Skip prm #1 
    **   .. 
    **  } 
    **  logit("error","illegal value : %s",somevalue); 
    ** 
    */ 

    $.vsprintf=function(args,offset) 
    { 
     if(offset === undefined) 
     { 
      offset=0; 
     } 
     return _sprintf_(args[offset],args,offset+1); 
    } 


    /* 
    ** logging using formatted messages 
    ** ================================ 
    ** 
    ** If you _hate_ debugging with alert() as much as I do, you might find the 
    ** following routines valuable. 
    ** 
    ** jQuery.alertf("The variable 'str' contains: '%s'",str); 
    **  Show an alert message with a printf-like argument. 
    ** 
    ** jQuery.logf("This is a log message, time is: %d",(new Date()).getTime()); 
    **  Log the message on the console with the info level 
    ** 
    ** jQuery.errorf("The given value (%d) is erroneous",avalue); 
    **  Log the message on the console with the error level 
    ** 
    */ 

    $.alertf=function() 
    { 
     return alert($.vsprintf(arguments)); 
    } 

    $.vlogf=function(args) 
    { 
     if("console" in window) 
     { 
      console.info($.vsprintf(args)); 
     } 
    } 

    $.verrorf=function(args) 
    { 
     if("console" in window) 
     { 
      console.error($.vsprintf(args)); 
     } 
    } 

    $.errorf=function() 
    { 
     $.verrorf(arguments); 
    } 

    $.logf=function() 
    { 
     $.vlogf(arguments); 
    } 


    /*------------------------------------------------------------------------------------------- 
    ** 
    ** Following code is private; don't use it directly ! 
    ** 
    **-----------------------------------------------------------------------------------------*/ 

    FREGEXP = /^([^%]*)%([-+])?(0)?(\d+)?(\.(\d+))?([doxXcsf])(.*)$/; 
    HDIGITS = ["0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"]; 

    function _empty(str) 
    { 
     if(str===undefined || str===null) 
     { 
      return true; 
     } 
     return (str == "") ? true : false; 
    } 

    function _int_(val) 
    { 
     return Math.floor(val); 
    } 

    function _printf_num_(val,base,pad,sign,width) 
    { 
     val=parseInt(val,10); 
     if(isNaN(val)) 
     { 
      return "NaN"; 
     } 
     aval=(val<0)?-val:val; 
     var ret=""; 

     if(aval==0) 
     { 
      ret="0"; 
     } 
     else 
     { 
      while(aval>0) 
      { 
       ret=HDIGITS[aval%base]+ret; 
       aval=_int_(aval/base); 
      } 
     } 
     if(val<0) 
     { 
      ret="-"+ret; 
     } 
     if(sign=="-") 
     { 
      pad=" "; 
     } 
     return _printf_str_(ret,pad,sign,width,-1); 
    } 

    function _printf_float_(val,base,pad,sign,prec) 
    { 
     if(prec==undefined) 
     { 
      if(parseInt(val) != val) 
      { 
       // No decimal part and no precision -> use int formatting 
       return ""+val; 
      } 
      prec=5; 
     } 

     var p10=Math.pow(10,prec); 
     var ival=""+Math.round(val*p10); 
     var ilen=ival.length-prec; 
     if(ilen==0) 
     { 
      return "0."+ival.substr(ilen,prec); 
     } 
     return ival.substr(0,ilen)+"."+ival.substr(ilen,prec); 
    } 

    function _printf_str_(val,pad,sign,width,prec) 
    { 
     var npad; 

     if(val === undefined) 
     { 
      return "(undefined)"; 
     } 
     if(val === null) 
     { 
      return "(null)"; 
     } 
     if((npad=width-val.length)>0) 
     { 
      if(sign=="-") 
      { 
       while(npad>0) 
       { 
        val+=pad; 
        npad--; 
       } 
      } 
      else 
      { 
       while(npad>0) 
       { 
        val=pad+val; 
        npad--; 
       } 
      } 
     } 
     if(prec>0) 
     { 
      return val.substr(0,prec); 
     } 
     return val; 
    } 

    function _sprintf_(fmt,av,index) 
    { 
     var output=""; 
     var i,m,line,match; 

     line=fmt.split("\n"); 
     for(i=0;i<line.length;i++) 
     { 
      if(i>0) 
      { 
       output+="\n"; 
      } 
      fmt=line[i]; 
      while(match=FREGEXP.exec(fmt)) 
      { 
       var sign=""; 
       var pad=" "; 

       if(!_empty(match[1])) // the left part 
       { 
        // You can't add this blindly because mozilla set the value to <undefined> when 
        // there is no match, and we don't want the "undefined" string be returned ! 
        output+=match[1]; 
       } 
       if(!_empty(match[2])) // the sign (like in %-15s) 
       { 
        sign=match[2]; 
       } 
       if(!_empty(match[3])) // the "0" char for padding (like in %03d) 
       { 
        pad="0"; 
       } 

       var width=match[4]; // the with (32 in %032d) 
       var prec=match[6]; // the precision (10 in %.10s) 
       var type=match[7]; // the parameter type 

       fmt=match[8]; 

       if(index>=av.length) 
       { 
        output += "[missing parameter for type '"+type+"']"; 
        continue; 
       } 

       var val=av[index++]; 

       switch(type) 
       { 
       case "d": 
        output += _printf_num_(val,10,pad,sign,width); 
        break; 
       case "o": 
        output += _printf_num_(val,8,pad,sign,width); 
        break; 
       case "x": 
        output += _printf_num_(val,16,pad,sign,width); 
        break; 
       case "X": 
        output += _printf_num_(val,16,pad,sign,width).toUpperCase(); 
        break; 
       case "c": 
        output += String.fromCharCode(parseInt(val,10)); 
        break; 
       case "s": 
        output += _printf_str_(val,pad,sign,width,prec); 
        break; 
       case "f": 
        output += _printf_float_(val,pad,sign,width,prec); 
        break; 
       default: 
        output += "[unknown format '"+type+"']"; 
        break; 
       } 
      } 
      output+=fmt; 
     } 
     return output; 
    } 

})(jQuery); 

Answer 2

這裏我超級簡單的解決方案，它可以（在任意數量的變化4）處理%s，%d和%04d

function sprintf(str) { 
    var args = arguments, i = 1; 

    return str.replace(/%(s|d|0\d+d)/g, function (x, type) { 
     var value = args[i++]; 
     switch (type) { 
     case 's': return value; 
     case 'd': return parseInt(value, 10); 
     default: 
      value = String(parseInt(value, 10)); 
      var n = Number(type.slice(1, -1)); 
      return '0'.repeat(n).slice(value.length) + value; 
     } 
    }); 
}