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

Posted by Shyam Gupta
Shyam Gupta
7,757 Points

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?

Barry Ort
Barry Ort
12,373 Points

can you supply your code?

Shyam Gupta
Shyam Gupta
7,757 Points 
window.setTimeout((a_string) => {
console.log(a_string);

},2000,'Hello');

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 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).

Sumeet Kumar
Sumeet Kumar
908 Points

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