actionscript-3 - 我如何在 Flex 中找到该字符串包含超过 6 次的字符？

Question

我想实现一个算法/验证。如何确定一个字符串在 Flex 中是否包含超过 6 次的特定字符？

Answer 1

有两种方法，我能想到：

1. 像这样使用RegExp和.replace()：

   var ch:String = "a";    //Character, that must be checked
   var text:String = "This is an example to show how many times '"+ch+"' occured.";
   //Matches non-`ch` characters
   var regexp:RegExp = new RegExp("[^"+ch+"]","g");   
   //Replacing non-`ch` characters with empty string
   var timesOccured:Number = text.replace(regexp,"").length;  
   trace(text, ": " ,timesOccured );
   

2. 像这样使用RegExp和.match()：

   var ch:String = "a";    //Character, that must be checked
   var text:String = "This is an example to show how many times '"+ch+"' occured.";
   //Matches `ch` characters
   var regexp:RegExp = new RegExp(ch,"g");
   var matches:Array = text.match(regexp);
   var timesOccured:Number = 0;
   //`matches` can be 'null', so we are performing additional check
   if( matches ){   
       timesOccured = matches.length;
   }
   trace(text, ": " ,timesOccured );
   

现在，当您拥有 时timesOccured，您可以轻松地进行验证：

if( timesOccured > 6 ){
   //Do some stuff
}else{
   //Do other stuff
}    

警告：如果您ch是正则表达式的特殊字符，如., +, (, ], \, 等...，您需要在将其传递给变量之前对其进行转义：regexp

ch = ch.replace(new RegExp("[.*+?|()\\[\\]{}\\\\]", "g"), "\\$&");

Answer 2

正则表达式的更简单替代方法如下：

var str:String = "This is an example to show how many...";
//find occurrences for character 'a'

trace("Ocurrences:" + str.split('a').length-1);