js search match indexof

 

 

String 的search方法和match方法 
       var  str="Define a class with a Class Definition.";
        var searchValue=/[A-Za-z]lass/g;
        //搜索第一个可以匹配的位置，该语句返回9
        document.write(str.search(searchValue),"<br>");
        //返回所有匹配的子字符串，该语句返回Class和class
        document.write(str.match(searchValue),"<br>");

 

<title>返回一个字符串在另一个字符串中出现的次数</title>
    <script type="text/javascript">
        var  str="Define a class with a class Definition.";
        var searchValue="class";
        //定义出现次数的变量
        var searchCount=0;
        //查看子字符串第一次在字符串中出现的位置
        var fromIndex =str.indexOf(searchValue);
        while(fromIndex!=-1){
            searchCount++;
            //再次进行查询，查询的开始位置为子字符串出现的位置加上子字符串的长度
            fromIndex=str.indexOf(searchValue,fromIndex+searchValue.length);
        }
        document.write("“",searchValue,"”在字符串",str,"“中出现的次数为：",searchCount,"次<br>");
    </script>

      var  oldstr="Define a class with a Class Definition.";
         document.write(oldstr,"<br>");
        var newStr=oldstr.replace("class","abc");
        document.write(newStr,"<br>");
        //使用正则表达式匹配药替换的字符串
        var searchValue=/class/gi;
        var newstr2=oldstr.replace(searchValue,'abc');
        document.write(newstr2,"<br><br>");
        //更多的替换字符串
        //替换函数
        function replaceStr(str){
            //将参数转换成大写并返回
            return str.toUpperCase();
        }
       var newstr3=oldstr.replace("class",replaceStr("abc"));
        document.write(newstr3,"<br>");