How do I check if a value is an empty or whitespace-only string in JavaScript?
Antek N

To check if a value is an empty or whitespace-only string in JavaScript, you can use a combination of string manipulation and conditional checks. Here's a step-by-step guide on how to achieve this: 1. Start with the value that you want to check. Let's assume the value is stored in a variable calledmyValue. 2. Use thetrim() method on the value to remove leading and trailing whitespace characters. Thetrim() method returns a new string with the whitespace removed.

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   const trimmedValue = myValue.trim();

3. Check if the trimmed value is an empty string. Use thelength property to check if the length of the trimmed value is zero.

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   const isEmpty = trimmedValue.length === 0;

TheisEmpty variable will betrue if the trimmed value is empty or contains only whitespace characters, andfalse otherwise. 4. Optionally, if you want to check for whitespace-only strings separately from empty strings, you can use a regular expression to match whitespace characters. Use thetest() method of the regular expression to check if the trimmed value matches the pattern.

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   const whitespaceRegex = /^\s*$/;
   const isWhitespaceOnly = whitespaceRegex.test(trimmedValue);

TheisWhitespaceOnly variable will betrue if the trimmed value contains only whitespace characters, andfalse otherwise. Here's a complete example:

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const myValue = '     ';
const trimmedValue = myValue.trim();
const isEmpty = trimmedValue.length === 0;
const whitespaceRegex = /^\s*$/;
const isWhitespaceOnly = whitespaceRegex.test(trimmedValue);

console.log(isEmpty); // Output: true
console.log(isWhitespaceOnly); // Output: true

By applying thetrim() method and performing conditional checks, you can determine if a value is an empty string or contains only whitespace characters in JavaScript.

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