Regular Expression for IP address won't work with RegEx(param), only works with ...

Hi all,

I dont know why but tests reveal that if I use "variable.value" and pass that info to the valGlobal below, the regular expressions won't work! what can I do to dix this?

if (globalValueControl.value != "" && itemValueTypeControl.value != "" )
{
//var valGlobal = new RegExp(itemValueTypeRegExControl.value); // it does not validate the value properly
//var valGlobal = itemValueTypeRegExControl.value; // Object does not suppot this property or method
//var valGlobal = new RegExp(/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/); // it works fine
var valGlobal = /^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/; // it works fine

if (!valGlobal.test(globalValueControl.value))
{
alert("Test Failed! Global value: " + itemValueTypeErrorControl.value);
formIsValid=false;
}
}

Thank you!

 

How is this a regex for IP address? It fails completely with my own IP (2001:5c0:a043:5ae0:3::xxxx)

 

Anybody please knows why the constructor RegEx WILL NOT accept a variable.value ? it only works when I type the pattern in it parameter.

@Krsix... not sure, it works for me: 10.10.10.10, 192.1.1.1, etc....

 

Your regexp contains backslash (\) character. Try this javascript in your browser to help understand.

var str = "aaa\bbb"; 
alert(str);

Code (markup):

You don't see the backslash \ in the string. The backslash must be quoted as \\ . Try,

var str = "aaa\\bbb"; 
alert(str);

Code (markup):

Now you get what you want. So you have to quote the string that has \ in it before process regexp. You can use the following method the quote the string.

String.prototype.quote = function() {
    return this.replace(/([\\])/g,"$1$1");
}

Code (markup):

So try,

var valGlobal = new RegExp(itemValueTypeRegExControl.value.quote());

Code (markup):

Yu can test you regexp in the online regexp tester

 

Thanks for replying. I've read somewhere about the issue and had tried that before.
By using alert(string) I am able to see the string with the extras "\" however the RegEx will still fail every time I type in a IP address