✅ Array.prototype.every() Polyfill
Category: js / polyfills
Difficulty: medium
The every() method tests whether all elements in the array pass the test implemented by the provided function. ✅ Implementation [code example] How It Works Checks if callback is a function If not, throws a TypeError (same behavior as Array.prototype.every). Iterates through the array Calls callback for each element with (element, index, array). Uses .call(thisArg, ...) to bind thisArg if provided. Returns early if any test fails If callback returns false for any element, customEvery immediately returns false (optimized). Returns true if all tests pass If all elements satisfy the condition, it returns true. Edge Cases Handled ✔ Empty array always returns true ✔ Stops checking as soon as one element fails (Optimized) ✔ Works with thisArg binding ✔ Throws an error if callback is not a function This implementation is efficient, clean, and mirrors Array.prototype.every exactly. <!-- quiz-start --> Q1: What does [].customEvery(x => x > 0) return? [x] true [ ] false [ ] undefined [ ] An error is thrown Q2: When does every() return false? [ ] When all elements pass the test [x] When any single element fails the test [ ] Only when all elements fail the test [ ] When the array is empty...