1 function a(val)
2 {
3 var re = /^/d+$/g;
4 alert(re.lastIndex);
5 return re.test(val);
6 }
7 alert(a(5));
8 alert(a(6));

1 function a(val)

2
3 {
4
5 var re = /^/d+$/g;
6
7 if((""+val).match(re))
8
9 return true;
10
11 else
12
13 return false;
14
15 }
16
17 alert(a(5));
18
19 alert(a(6));

1 function a(val)
2
3 {
4
5 var re = new RegExp("^[0-9]+$");//或者var re=/^/d+$/;
6
7 return re.test(val);
8
9 }
10
11 alert(a(5));
12
13 alert(a(6));
14
15

1 function a(val)
2
3 {
4
5 var re = /^/d+$/g;
6
7 re.lastIndex=0;//重置lastIndex為0
8
9 return re.test(val);
10
11 }
12
13 alert(a(5));
14
15 alert(a(6));