Creates a 2D array that contains a pascal's triangle.

pascals-triangle.js

function pascal(rows) {

    var pascalsTriangle = [];
    
    for (var row=1; row<=rows; row++) {
        
        var rowResults = [];
        
        if (pascalsTriangle[row-2]) {
            var aboveRow = pascalsTriangle[row-2];
            
            for (var i=0; i<row; i++) {
                if (aboveRow[i-1] && aboveRow[i]) {
                    rowResults.push(aboveRow[i-1] + aboveRow[i]);
                }
                else {
                    rowResults.push(1);
                }
            }
        }
        else {
            rowResults.push(1);
        }
        pascalsTriangle.push(rowResults);
    }
    console.log(pascalsTriangle);
    return pascalsTriangle;
}