Triangle.js

/*
 * Triangle
 *
 * INPUT:
 * - a number N
 *
 * OUPUT: (eg for N=5)
 * #
 * ##
 * ###
 * ####
 * #####
 *
 */

function Line(N) {
    return "#".repeat(N);
}

function Triangle(N) {
    for (var i = 1; i <= N; ++i) {
        console.log(Line(i));
    }
}

Triangle(5);
Triangle(3);