[英]Regular Expression in JavaScript to allow only numbers with optional 2 decimals
I want to write a regular expression in which allows 我想写一个允许的正则表达式
For example: 例如:
The use of this regular expression would be like on javascript event 这个正则表达式的使用就像在javascript事件上一样
<input type="text" onKeyPress="validatenumber(event);" /><br>
My code is
我的代码是
function validatenumber(evt) {
var theEvent = evt || window.event;
var key = theEvent.keyCode || theEvent.which;
key = String.fromCharCode( key );
var regex = /^[0-9\b]+$/; // allow only numbers [0-9]
if( !regex.test(key) ) {
theEvent.returnValue = false;
if(theEvent.preventDefault) theEvent.preventDefault();
}
}
I want to change only this line with the new regex: 我想用新的正则表达式只改变这一行:
var regex = /^[0-9\b]+$/; // allow only numbers [0-9]
Here it is: 这里是:
/^\d*(?:\.\d{1,2})?$/
Working Demo: http://jsfiddle.net/qd7BL/ 工作演示: http : //jsfiddle.net/qd7BL/
find the final solution at least 至少找到最终解决方案
<input id="txtId" type="text" onkeyup="NumAndTwoDecimals(event , this);"></input>
and the 和
function NumAndTwoDecimals(e , field) {
var val = field.value;
var re = /^([0-9]+[\.]?[0-9]?[0-9]?|[0-9]+)$/g;
var re1 = /^([0-9]+[\.]?[0-9]?[0-9]?|[0-9]+)/g;
if (re.test(val)) {
//do something here
} else {
val = re1.exec(val);
if (val) {
field.value = val[0];
} else {
field.value = "";
}
}
}
这个正则表达怎么样:
^\d*(?:\.\d\d)?$
This below simple html code will validate the required value and also +ve & -ve numbers of atleast 1 digit additionally optional 2 digits after decimal point. 以下简单的html代码将验证所需的值以及至少1位数的+ ve和-ve数,另外还可选小数点后2位数。
JS Code: JS代码:
function validateNum() {
/*
For mandatry input field, use variable: "patForReqdFld".
For optional input filed, use variable: "patForOptFld".
*/
var patForReqdFld = /^(\-)?([\d]+(?:\.\d{1,2})?)$/;
var patForOptFld = /^(\-)?([\d]*(?:\.\d{1,2})?)$/;
var value = document.getElementById('txtNum').value;
if(patForReqdFld.test(value)) {
alert('Valid Number: ' + value);
} else {
alert('Invalid Number: ' + value);
}
}
HTML Code: HTML代码:
<label>Enter Number: </label>
<input type="text" id="txtNum" onBlur="validateNum()"/>
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