JS Practice — Built-in Objects

Array.prototype.every() — check all positive

📖 Usage Example

const nums = [2, 4, 6, 8]
nums.every(n => n > 0)  // → true
nums.every(n => n > 5)  // → false

Use every() to check whether all elements in an array satisfy a condition.

Array.prototype.every()

Array.prototype.every(callback) returns true if the callback returns a truthy value for every element, and false as soon as any element fails the test. It short-circuits on the first failing element.

Challenge: Implement allPositive(nums) that returns true if every number in the array is greater than 0.

allPositive([1, 2, 3])    // → true
allPositive([1, -1, 3])   // → false

💡 Hints (2)

• `every()` short-circuits — it stops as soon as it finds a failing element.
• An empty array always returns `true` with `every()` — this is called vacuous truth.