How to retrieve a variable number from a JavaScript string

Question

How to retrieve a variable number from a JavaScript string

In an ASP.NET environment, I am working with a string called ctl00_ContentPlaceHolder1_lstViewFormulas_ctrl06_lblCountDown, which will be passed into a JavaScript function using the sender parameter from my button control...

<asp:Button ID="buttStartTimer" runat="server" CausesValidation="false" OnClientClick="javascript:countdown(this);" Text="Start" />

Here is the JavaScript function:

function test(sender) {

}

I need to extract the number that directly follows "ctrl" in the string. For example, in the above scenario, the number would be 06 (ctrl06_lblCountDown)

Is there a way to achieve this extraction using JavaScript?

Thank you

javascript asp.net regex

Answer 1

Answer №1

let text = "ctl00_ContentPlaceHolder1_lstViewFormulas_ctrl06_lblCountDown",
    findNumber = text.match(/.*ctrl(\d+).*/)[1];

Example in action: http://jsfiddle.net/RXGb2/

Answer 2

let text = "ctl00_ContentPlaceHolder1_lstViewFormulas_ctrl06_lblCountDown",
    findNumber = text.match(/.*ctrl(\d+).*/)[1];

Example in action: http://jsfiddle.net/RXGb2/

Answer 3

Answer №2

If you need to retrieve a number from a string, using regex can make the process quick and easy:

var text = "ctl00_ContentPlaceHolder1_lstViewFormulas_ctrl06_lblCountDown";
var number = parseInt(text.match(/_ctrl([\d]*)_/)[1], 10);

For a more cautious approach:

var text = "ctl00_ContentPlaceHolder1_lstViewFormulas_ctrl06_lblCountDown";
var parts = text.match(/_ctrl([\d]*)_/), number;
if(parts.length > 1) {
    number = parseInt(parts[1], 10);
}

Answer 4

If you need to retrieve a number from a string, using regex can make the process quick and easy:

var text = "ctl00_ContentPlaceHolder1_lstViewFormulas_ctrl06_lblCountDown";
var number = parseInt(text.match(/_ctrl([\d]*)_/)[1], 10);

For a more cautious approach:

var text = "ctl00_ContentPlaceHolder1_lstViewFormulas_ctrl06_lblCountDown";
var parts = text.match(/_ctrl([\d]*)_/), number;
if(parts.length > 1) {
    number = parseInt(parts[1], 10);
}

Answer 5

Answer №3

Here is a possible solution you can use:

let string = 'ctrl06_lblCountDown',
    numericArray = [],
    numericString,
    number,
    i = 0,
    length = 0;

numericArray = string.match(/[0-9]/g);

length = numericArray.length;

numericString = '';
for(i = 0; i < length; i++){
    numericString += numericArray[i];
}

number = parseInt(numericString, 10);

Answer 6

Here is a possible solution you can use:

let string = 'ctrl06_lblCountDown',
    numericArray = [],
    numericString,
    number,
    i = 0,
    length = 0;

numericArray = string.match(/[0-9]/g);

length = numericArray.length;

numericString = '';
for(i = 0; i < length; i++){
    numericString += numericArray[i];
}

number = parseInt(numericString, 10);

How to retrieve a variable number from a JavaScript string

Answer №1

Answer №2

Answer №3

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