Transform a string to lower case

What is lower case?

Lower case refers to the set of small or lowercase letters in a given writing system, such as the English alphabet. Lower case letters are typically used in the body of text, as opposed to upper case letters which are used for emphasis or to indicate a title or heading.

In English, lower case letters include a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, and z. In contrast, upper case letters include A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, and Z.