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JavaScript JavaScript and the DOM (Retiring) Responding to User Interaction Delaying Execution with setTimeout()

How is this function executing when it's not being called? Isnt the code just a function declaration?

How is this function executing when it's not being called? Isnt the code just a function declaration?

can you supply your code?

window.setTimeout((a_string) => {
console.log(a_string);

},2000,'Hello');

1 Answer

Steven Parker
Steven Parker
229,018 Points

You're right, the function being declared as an argument to setTimeout isn't being called right now. This type of argument is know as a "callback" function. The setTimeout function saves it and then calls it later (in this case, after 2 seconds).

How the function parameter (a_string) takes "hello" as its value