JS Built-ins
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ArrayArray.prototype.everyintermediate

Array.prototype.every() — check all even

📖 Usage Example
const nums = [1, 2, 3, 4]
nums.every(n => n > 0)  // → true  (all positive)
nums.some(n => n > 3)   // → true  (at least one > 3)

Use every() when all elements must pass, and some() when at least one must pass.

Array.prototype.every() vs some()

every() requires all elements to pass; some() requires at least one. Understanding this distinction is essential for writing correct predicates.

Challenge: Implement allEven(nums) that returns true if every number in the array is even.

allEven([2, 4, 6])   // → true
allEven([2, 3, 6])   // → false
💡 Hints (2)
  • • `n % 2 === 0` is true for even numbers.
  • • To check if at least one is even, you would use `some()` instead.