matrix =
[[7, 2, 7, 2, 8],
[2, 9, 4, 1, 7],
[3, 8, 6, 2, 4],
[2, 5, 2, 9, 1],
[6, 6, 5, 4, 5]];

matrix.forEach(function(item, ind){
    matrix[0].forEach(function(item0, ind0){
        console.log(item0);
    })
    return false;
})