Example of a function using JavaScript to copy the provided text to the clipboard

copyText.func.js

const onClickCopyText = text => {
    // Step 1: Using Clipboard API
    if (window?.navigator?.clipboard && window?.navigator?.clipboard?.writeText) {
        return window.navigator.clipboard.writeText(text);
    } else {
        return fallbackCopyTextToClipboard(text);
    }
};

const fallbackCopyTextToClipboard = text => {
    // Step 2: Alternative Copying Text without Clipboard API
    const textarea = document.createElement('textarea');

    textarea.value = text;
    textarea.setAttribute('readonly', '');
    textarea.style.position = 'absolute';
    textarea.style.left = '-9999px';
    document.body.appendChild(textarea);
    textarea.select();

    try {
        const successful = document.execCommand('copy');
        const msg = successful ? 'successful' : 'unsuccessful';
        console.log(`Fallback: Copying text command was ${msg}`);
        return successful;
    } catch (err) {
        console.error('Fallback: Oops, unable to copy', err);
        return false;
    } finally {
        document.body.removeChild(textarea);
    }
};

// Test Way 1
onClickCopyText('This text will be copied to clipboard.')
    .then(() => console.log('async: Success!'))
    .catch(err => console.error('async: Failed!.', err));

// Test Way 2
const copied = onClickCopyText('This text will be copied to clipboard.');
if (copied) {
    console.log('Sync: Success!');
} else {
    console.error('Sync: Failed!');
}