I was looking for javascript documentation and found this
const log = document.getElementById('log');
document.addEventListener('keydown', logKey);
function logKey(e) {
log.textContent += ` ${e.code}`;
}
I don't understand how logkey function is working in addeventlistener . when I press a key, the console prints its code but logkey is not having any parameters in addeventlistener. How did it print e.code ?
You pass the function as a parameter to the eventListener. The eventListener calls the logKey function with the event as a function parameter.
See in the following example how a parameter is passed on to the function:
function func1(function_as_parameter){
function_as_parameter('Shivam');
}
function helloWordFunction(name){
console.log(`Hello ${name}!`);
}
func1(helloWordFunction); // Hello Shivam!