Required attribute in an input text javascript

I want to put the required attribute in this input created in javascript

  // Celula 4 -Local
    // Cria um <td>
    var locall = row.insertCell(4);
    // Cria o input
    var local = document.createElement('input');
    // Input do tipo texto
    local.type = 'text';
    local.name = 'local[]';
    local.id = 'local';
    local.placeholder='Local';
    local.title = "Local";
    local.className = "form-control";
    locall.appendChild(local);