Reversing a string means the last character becomes the first, the second-to-last becomes the second, and so on. For "CodeSignal," reversing gives "langiSedoC."
The sum of the first 5 natural numbers is 1 + 2 + 3 + 4 + 5 = 15. The sum of the array is 1 + 2 + 4 + 5 = 12. The missing number is 15 - 12 = 3.
A palindrome is a string that reads the same backward as forward. Among the options, only "level" satisfies this property.
The vowels in the English language are a, e, i, o, u. In "CodeSignal," the vowels are o, e, i, which total 3.
The sum of the array [3, 5, 7, 2] is calculated as 3 + 5 + 7 + 2 = 17.
