JAVASCRIPT - HOW TO Add Non Duplicates to Textarea - Javascript Source Code

JAVASCRIPT - HOW TO Line by Line Strings to Textarea Prevent the Addition of Duplicates to the Textarea.

The Javscript function below takes items in a textarea and removes any duplicate lines. This Javascript function does this without long processor hogging loops by ...

1. Putting the contents of the textarea into an array by splitting the value in the textarea, line by line, while simutaneously removing any blank or emppty lines.
2. The array is then turn into a Javascript SET which automatically removes duplicates from the array.
3. The SET is then converted back to an array using the built in Javascript ARRAY.FROM.
4. The array is then joined or put back together, each element of the array separated by a carriage return and then this is put back into the textarea.

function funcAddNoDupToTextarea(idOfTextarea){ // GET HANDLE TO TEXTAREA WE WISH TO REMOVE DUPLICATES FROM let ta = document.getElementById(idTextArea); // REMOVE ALL BLANK LINES let varArrLines = ta.value.replace(/^\s*[\r\n]/gm, '').trim().split('\n').filter(line => line); // TURN ARRAY TO SET WHICH AUTOMATICALLY REMOVES DUPLICATES let varUniqueLines = new Set(varArrLines); // CONVERT SET BACK TO ARRAY let varArrUniqueLines = Array.from(varUniqueLines); // PUT THE ARRAY BACK INTO THE TEXTAREA DUPLICATES REMOVED ta.value = varArrUniqueLines.join('\r\n'); }

Try this function to remove duplicates from a textarea yourself

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Remove Duplicates from Textarea