chessBoard.js

function getBoard(n) {
    "use strict";
    let html = `<div class="chessboard">\n`;

    for (let row = 0; row < n; row ++) {
        html += `   <div>\n`;
        for (let col = 0; col < n; col++) {
            let color = (row + col) % 2 == 0 ? 'black' : 'white';
            html += `    <span class="${color}"></span>\n`;
        }

        html += `</div>\n`;
    }

    html += `</div>`;
    return(html);
}

getBoard(3);