[fmmshadiq]

<script>
const workers = [
    {
        name : 'maxim',
        lastname : 'ivanov'
    },
    {
        name : 'ivan',
        lastname: 'borisov'
    }
];
function namestoupper(arr) {
    arr.forEach(obj => {
    for (let key in obj) {
    obj[key.toUpperCase()] = obj[key];
    delete obj[key]
    }
    })
}
namestoupper(workers);
document.write(`<pre>${JSON.stringify(workers, "", 1)}</pre>`)
</script>

Понял, спасибо