심재운 블로그

https://stackoverflow.com/a/105074

function guid() {
  return s4() + s4() + '-' + s4() + '-' + s4() + '-' +
    s4() + '-' + s4() + s4() + s4();
}

function s4() {
  return Math.floor((1 + Math.random()) * 0x10000)
    .toString(16)
    .substring(1);
}

document.getElementById('jsGenId').addEventListener('click', function() {
  document.getElementById('jsIdResult').value = guid();
})

input { font-family: monospace; }

<button id="jsGenId" type="button">Generate GUID</button>
<br>
<input id="jsIdResult" type="text" placeholder="Results will be placed here..." readonly size="40"/>