<script language="JavaScript"><!--
var s1 = "abc";
var s2 = "abcdefg";
var s3 = "aabcdefg";
alert(s2.indexOf(s1)==0);
alert(s3.indexOf(s1)==0);
//--></script>
var s1 = "abc";
var s2 = "abcdefg";
var s3 = "aabcdefg";
alert(s2.indexOf(s1)==0);
alert(s3.indexOf(s1)==0);
//--></script>
var s1 = "abc";
var s2 = "bcd";
var s3 = "abcdefg";
var s4 = "aabcdefg";
alert(s3.indexOf(s1)==0);结果是true
alert(s3.indexOf(s2)==0);结果是false能实现吗?
//--></script>
var a = /abc/;
var b = "abcsdfsd";
alert(a.test(b));
</script>
<script language=JavaScript>
a="abc"
b="abcd"
c="aabcd"
d=eval("/^"+a+"/")
alert(d.test(b))
alert(d.test(c))
</script>