Flash cards
Review the key moves
What is the main idea behind React Events?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
<___ onClick={shoot}>Take the Shot!</button>Put the learning moves in the order that makes the concept easiest to apply.
Just like HTML DOM events, React can perform actions based on user events.
React has the same events as HTML: click, change, mouseover etc.
Adding Events
React events are written in camelCase syntax:
onClick instead of onclick .
React event handlers are written inside curly braces:
onClick={shoot} instead of onclick="shoot()" .
React
<button onClick={shoot}>Take the Shot!</button>HTML
<button onclick="shoot()">Take the Shot!</button>Example
Put the shoot function inside the Football component:
function Football() {
const shoot = () => {
alert("Great Shot!");
}
return ( <button onClick={shoot}>Take the shot!</button> );
}
createRoot(document.getElementById('root')).render( <Football /> );Passing Arguments
To pass an argument to an event handler, use an arrow function.
Example
Send "Goal!" as a parameter to the shoot function, using arrow function:
function Football() {
const shoot = (a) => {
alert(a);
}
return ( <button onClick={() => shoot("Goal!")}>Take the shot!</button> );
}
createRoot(document.getElementById('root')).render( <Football /> );React Event Object
Event handlers have access to the React event that triggered the function.
In our example the event is the "click" event.
Example
Arrow Function: Sending the event object manually:
function Football() {
const shoot = (a, b) => {
alert(b.type);
/* 'b' represents the React event that triggered the function, in this case the 'click' event
*/
}
return ( <button onClick={(event) => shoot("Goal!", event)}>Take the shot!</button> );
}
createRoot(document.getElementById('root')).render( <Football /> );This will come in handy when we look at Form in a later chapter.