[英]Regular Expression to accept only positive number and decimals (only end with .5 .0 or integer accepted)
我需要JavaScript中的正则表达式,该表达式只接受以.5或.0结尾的正数和小数。
(^\d*\.?\d*[1-9]+\d*$)|(^[1-9]+\d*\.\d*$)
这就是我所拥有的,但是我不知道如何更改它以拒绝0和0.0,并拒绝以.1 .2 .3 .4 .6 .7 .8 .9结尾的那些
Accept:
0.5
1.0
1.5
2.0
2.5
3.0
1
2
3
4
但
Reject:
-1.0
-0.5
-0.0
-0.1
-0.7
0
0.0
0.1
0.9
0.4
1.3
1.11
1.51
2.01
将数字乘以2,看是否为整数:
function check(v) { return v > 0 && !(v*2 % 1); } var tests = [ 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 1, 2, 3, 4, -1.0, -0.5, -0.0, -0.1, -0.7, 0.0, 0.1, 0.9, 0.4, 1.3, 1.11, 1.51, 2.01]; tests.forEach(v => console.log(v, check(v) ? "passes": "fails"));
以下正则表达式如何: ^\\d*\\.\\d{0,}(0|5)
?
这里是解释:
^ //line start
\d* //any number (or none) occurrences of any number
\. //decimal dot
\d{0,} //0 or more digits (actually the same as * - you can use it here too)
(0|5) //ends with 0 or 5
试试吧 :
<html>
<head>
</head>
<body>
<script>
var patt = /^(\+)?\d+(\.[05])?$/;
var number = 1.5;
if (number > 0 && patt.test(number))
alert("Number is valid");
else
alert("Number is Invalid");
</script>
</body>
</html>
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.