why it's showing cannot set textContent = null

Question

my code is
document.getElementById('score-0').textContent = 0;
document.getElementById('score-1').textContent = 0;
document.getElementById('current-0').textContent = 0;
document.getElementById('current-1').textContent = 0;
document.getElementById('name-0').textContent = 'Player 1'
document.getElementById('name-1').textContent = 'Player 2'
document.querySelector('.player-0-panel').classList.remove ('winner');
document.querySelector('.player-1-panel').classList.remove ('winner');

}

Answer 1

Two reasons getElementById fails are:
1. DOM isn't ready, use window.onload() or jQuery 'ready' pattern
2. id's aren't set properly

A CodePlayground link would help people be more specific for your case.

Answer 2

so what's the solution to do it without a framework.