Clipboard - Web API | MDN (mozilla.org)

if (typeof navigator.clipboard === 'object') {
if (navigator.clipboard.readText(). === 'hoge'){
navigator.clipboard.writeText('hogehoge');
} else {
navigator.clipboard.writeText('hoge');
}


if (typeof navigator.clipboard === 'object') {

navigator.clipboard.writeText('hoge');
}

navigator.clipboard.readText()
    .then((data) => console.log(data))
    .catch((e) => console.error('failed'));

document.getElementById('btn').addEventListener('click', async () => {
 const text = await navigator.clipboard.readText();
 console.log(text);
});


async () => {
 const text = await navigator.clipboard.readText();
 console.log(text);
};


    // IE
    if (typeof window.clipboardData === 'object') {
      window.clipboardData.setData('Text', value);