How to get HTTP user-agent header with js?

Question

For my project, I want to get and print the user-agent of my browser. I'm using javascript (with node) to accomplish my goal. How can I get and print the user-agent header without using the HTTP module and html if possible and inside of this blank function:

function userAgent() {
  
}

Answer 1

You can try this.

<script>
   window.onload = function () {
        var agent = navigator.userAgent.toLowerCase();
        if (agent.indexOf('chrome') != -1) { 
           alert('Chrome');
        }
        if (agent.indexOf('msie') != -1) {
           alert('Explorer');
        }
        if (agent.indexOf('safari') != -1) {
           alert('Safari');
        }
        if (agent.indexOf('firefox') != -1) {
           alert('Firefox');
        }
   }
</script>