My QTableWidget doesn't want to let me add a title to a new row with the button

[Prodeine]

try using this;

ui->tableWidget->insertRow(row)

count starts from 0 because nothing is there, row 0 is actually the index for the first item. every time you press the add button you will get a new line.


edit: you may also be trying to edit your headers, here is an example of something I am using right now.

void Resolver::on_pushButton_6_clicked()
{
    ui->calcResults->clear();
    ui->calcResults->setColumnCount(5);
    m_TableHeader<<"Bet"<<"Balance"<<"Wager"<<"Payout"<<"Profit"; // is a QStringList
    ui->calcResults->setHorizontalHeaderLabels(m_TableHeader);
 
......
 
 
    int count = ui->calcResults->rowCount();
    ui->calcResults->insertRow(count);

void Resolver::on_pushButton_6_clicked()
{
    ui->calcResults->clear();
    ui->calcResults->setColumnCount(5);
    m_TableHeader<<"Bet"<<"Balance"<<"Wager"<<"Payout"<<"Profit"; // is a QStringList
    ui->calcResults->setHorizontalHeaderLabels(m_TableHeader);

......


    int count = ui->calcResults->rowCount();
    ui->calcResults->insertRow(count);

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you will want to setVerticleHeaderLabels instead

https://doc.qt.io/qt-5/qtablewidget.html