Introduction to Option object_javascript in the drop-down menu-js tutorial

The Option object represents an Option in the drop-down list of HTML forms. Each time an & lt; option & gt; tag appears in an HTML form, an Option object is created. You can access an Option object through the elements [] array of the form, or by using document. getElementById (). 1. Create an Option object

1.1 var optionEle1 = document. createElement ('option ');

1.2 var optionEle2 = new Option (text, value, defaselecselected, selected );

2. options attributes

2.1 select. options returns the set of Option objects under the select tag.

3. Clear the drop-down menu

3.1 Use the for loop to delete, pay attention to the dynamic change of the array Length

3.2 select. options. length = 0;

4. Application