select in javascript code example

Example 1: select element in js

//<div id="demo-id"></div>
var elem1 = document.getElementById("demo-id");
//<div class="demo-class"></div>
var elem2 = document.getElementsByClassName("demo-class");
//<div name="demo-name"></div>
var elem3 = document.getElementsByName("demo-name");
//<p>Some text</p>
var elem4 = document.getElementsByTagName("p");

//<div id="demo-id"></div>
var elem1 = document.querySelector("#demo-id");
//<div class="demo-class"></div>
var elem2 = document.querySelectorAll(".demo-class");
//<div name="demo-name"></div>
var elem3 = document.querySelectorAll('[name="demo-name"]');
//<p>Some text</p>
var elem4 = document.querySelectorAll("p");

Example 2: js select option in form

<form name="AddAndEdit">
   <select name="list" id="personlist">
      <option value="P1">Person1</option>
      <option value="P2">Person2</option>
      <option value="P3">Person3</option>
   </select>
</form>

Example 3: select html js

var elem1 = document.getElementById("demo-id");
//<div class="demo-class"></div>
var elem2 = document.getElementsByClassName("demo-class");
//<div name="demo-name"></div>
var elem3 = document.getElementsByName("demo-name");
//<p>Some text</p>
var elem4 = document.getElementsByTagName("p");

//<div id="demo-id"></div>
var elem1 = document.querySelector("#demo-id");
//<div class="demo-class"></div>
var elem2 = document.querySelectorAll(".demo-class");
//<div name="demo-name"></div>
var elem3 = document.querySelectorAll('[name="demo-name"]');
//<p>Some text</p>
var elem4 = document.querySelectorAll("p");