MCQs on Array Methods

1. What is the output? [ 1 , 2 , 3 ]. forEach ( num => num * 2 ); Options: A) [2, 4, 6] B) undefined C) [1, 2, 3] D) Error ✅ Answer: B) undefined Explanation: forEach() does NOT return anything → returns undefined 2. What is the output? let result = [ 1 , 2 , 3 ]. map ( num => { if ( num > 1 ) return num * 2 ; }); console . log ( result ); Options: A) [2, 4, 6] B) [undefined, 4, 6] C) [4, 6] D) Error ✅ Answer: B) [undefined, 4, 6] Explanation: map() always returns same length For num = 1, nothin