js判断字符出现次数，字符包含及手机号码验证的小例子

<script>
function patch(re,s){ //参数1正则式，参数2字符串
re=eval_r("/"+re+"/ig"); //不区分大小写，如须则去掉i,改为 re=eval_r("/"+re+"/g")
var len = s.match(re).length;
return len;
}
var str="Hello World";

alert("num = " + patch("o",str));
</script>

<script> 
var reg1 =  /^13d{9}$/;
var reg2 =  /^15d{9}$/;
var reg3 =  /^18d{9}$/;
var bo = reg1.test(mobile) || reg2.test(mobile) || reg3.test(mobile);
alert(bo);
 //by www.jb200.com
</script>

<script>
var str= "Hello World"
var s = str.indexOf("Hello");
alert(s);
</script>