This example shows how to select entire input in a single click using javaScript.
Syntax:
<input onClick="this.select();" >
or
document.getElementById("ID").select();
Example-1: Using “this.select()”.
<!DOCTYPE html> <html>   <head>     <title>         Select all text in HTML        text input when clicked     </title>   </head>   <body>     <br> Input Text:     <br>     <input onClick="this.select();"            type="text"           value="neveropen"> </body>   </html>  | 
Output:
Before click:
After click:
Example-2: Using DOM Input Text select() Method
<!DOCTYPE html> <html>   <head>     <title>         Select all text in HTML       text input when clicked     </title> </head>   <body>     Input Text:     <br>     <input type="text"           value="neveropen"           id="eid">       <button type="button"             onclick="myFunction()">       Try it   </button>       <script>         function myFunction() {             document.getElementById(               "eid").select();         }     </script>   </body>   </html>  | 
Output:
Before click:
After click:

                                    