Why is a local variable just taken and set to zero?

Question

Node.js

Either I don't understand something, or JavaScript should be banned by law and equated with extremism...

async uploadCSV(file: Express.Multer.File) {
    const errorsOnLines: number[] = [];

    const csvString = Buffer.from(file.buffer).toString('utf-8');
    const pupils = await csvtojson({
        ignoreEmpty: true,
        maxRowLength: 9,
        delimiter: 'auto'
    }).fromString(csvString);

    pupils.forEach(async (pupil: createPupilDTO, index: number) => {
        pupil.age = moment(pupil.age, 'DD.MM.YYYY').toISOString();

        try {
            await this.PupilModel.validate(pupil);
        } catch (err) {
            errorsOnLines.push(index + 2);
        }
    });

    console.log(errorsOnLines)
}

If you start the debug mode and set breakpoints, you can see how the array is errorsOnLinesfilled with two, three values, and so on. But as soon as execution gets to console.log()I get [].

Help...

Answer 1

Or I don't understand something

Do not understand the meaning of the word asynchronous
console.log works out before anyone elseerrorsOnLines.push