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JavaScript Asynchronous Programming with JavaScript Asynchronous JavaScript with Callbacks Implement a Callback

Hernan Diaz
Hernan Diaz
7,197 Points

Why do we return callback return in getJSON(), this return is not used?

function getJSON(url, callback) { const xhr = new XMLHttpRequest(); xhr.open('GET', url); xhr.onload = () => { if(xhr.status === 200) { let data = JSON.parse(xhr.responseText); return callback(data); // <<<<<<<=========== HERE, we don't need it, do we? } }; xhr.send(); }

1 Answer

Farid Lavizadeh
Farid Lavizadeh
12,004 Points

I believe it's used for the parameter (json). Then json.people.map uses the "data" as argument for json.