You develop an HTML5 webpage. You have the following HTML markup:
<input type=”text” id=”username” />
You need to prevent users from entering specific characters into the username field.
What should you do?
A.
Using the keyup event, add an anonymous function that returns true when a specific character keycode
value is determined.
B.
Using the change event, add an anonymous function that returns true when a specific character keycode
value is determined.
C.
Using the keydown event, add an anonymous function that returns false when a specific character keycode
value is determined.
D.
Using the change event, add an anonymous function that returns false when a specific character keycode
value is determined.
Explanation:
The change event is fired for <input>, <select>, and <textarea> elements when a change to the element’s value
is committed by the user.
Use the change event and an anonymous function to detect illegal specific characters in the input.
onchange occurs when the input element loses focus and it will not preventusers from entering specific char.
keydown event can prevent a specific char when it returns false.
The answer should be C.
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Agree
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Nothing of those wont work.
It’s not enough to return false.
https://stackoverflow.com/questions/22708434/restrict-characters-in-input-field
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