Suggest an editImprove this articleRefine the answer for “every() in an array”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**The `every()` method** checks that all elements of an array satisfy a condition set by the passed callback function. If every element returns `true`, the method returns `true`; if at least one element does not match, it returns `false` and stops further checking. **Key point:** for an empty array, `every()` returns `true`.Shown above the full answer for quick recall.Answer (EN)ImageThe `every()` method checks that **all elements of the array** satisfy a condition set by the passed callback function. If *every* element returns `true`, the method returns `true`. If at least one element does not match, it returns `false` and **stops** further checking. ## Important points worth mentioning in an interview - `every()` **does not change the original array**. - As soon as an element is found for which the callback returned `false`, execution stops. - Returns a **boolean**. - Works only with the callback's logical result. - For an empty array `every()` returns **true** (this is an important, frequently asked feature). ## Signature ```js array.every((element, index, array) => { // return true/false }); ``` ## Example Let's check whether an array consists only of even numbers: ```js const numbers = [2, 4, 6, 8]; const allEven = numbers.every(num => num % 2 === 0); console.log(allEven); // true ``` If we add an odd number: ```js [2, 4, 5, 8].every(n => n % 2 === 0); // false ``` ## Example from real-world development Checking whether all users have passed verification: ```js const users = [ { name: 'Alex', verified: true }, { name: 'John', verified: true }, { name: 'Kate', verified: false }, ]; const allVerified = users.every(u => u.verified); console.log(allVerified); // false ``` ## Common pitfalls and interview questions #### 1) **Why does an empty array give true?** Because `every()` checks the condition "all elements satisfy". If there are no elements, there is no violation of the condition, so the result is considered **true by default**. This property is often called **"vacuous truth"**. #### 2) **Difference from some():** - `some()` -> at least one element must match - `every()` -> all elements must match - In short: - if `every()` returned `true`, `some()` can be either `true` or `false` - but if `some()` returned `false`, that does not mean `every()` will be trueFor the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.