Check out example codes for "html onkeyup". It will help you in understanding the concepts better.

Code Example 1

<input type="text"  onkeyup="myFunction()">

Code Example 2

<input type="text" onkeyup="myFunction()">

Code Example 3

A function is triggered when the user releases a key in the input field

Code Example 4

<input type="text" onkeyup="myFunction()"> //Or your Code

Learn ReactJs, React Native from akashmittal.com