正则表达式替换能指定次数吗

[locket]

RegExp(str,'gi');
如果我只想替换2次，3次或n次，该如何写

[xiongzhijian]

var count = 0;
function f2c(s,n) {
  var test = /(\d+(\.\d*)?)F\b/g;    // 初始化模式。
  return(s.replace
    (test,
      function($0,$1,$2) { 
        count < n ? return((($1-32) * 5/9) + "C") : return $1;
        count++;
      }
    )
  );
  document.write(f2c("Water freezes at 32F and boils at 212F. Water freezes at 32F and boils at 212F",3));
}

[xiongzhijian]

var count = 0;
function f2c(s,n) {
  var test = /(\d+(\.\d*)?)F\b/g;    // 初始化模式。
  return(s.replace
    (test,
      function($0,$1,$2) { 
        count < n ? return((($1-32) * 5/9) + "C") : return $1;
        count++;
      }
    )
  );
}

document.write(f2c("Water freezes at 32F and boils at 212F. Water freezes at 32F and boils at 212F",3));

[monexus]

str.replace(regexp, (function(){
	var limit = 3; // 替换次数
	return function(m){
		return 0 > --limit ? m : 'your replace';
	}
})());

[cuixiping]

str.replace(regexp, (function(){
    var limit = 3; // 替换次数
    return function(m){ return 0 > --limit ? m : 'your replace'; }
 })());

正解。
js闭包应用。

[xingqiliudehuanghun]

来个怪的

var s="123 123, ddd 123 ff 123 fff 123,123,123,123";
function replace(source,strF,strR,n){
   var a=s.split(strF);
   s=a.slice(0,n+1).join(strR)+(a.length>n+1?strF:"")+a.slice(n+1).join(strF);
   return s;
}

alert(replace(s,123,"[]",5));