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CreativeGvc B
Courses Plus Student 3,386 PointsCan you explain please what is a callback function?
Im a bit confused about this. What is a callback function in javascript?
Thanks!
2 Answers
Steven Parker
243,318 PointsOften, a function starts a process that will take some time to finish, like a screen animation or a network transmission. Rather than make your program wait, it returns right away so your program can keep going.
But as one of its arguments it takes a callback function, which is a function that will be called at some point in the future when the other process has finished.
CreativeGvc B
Courses Plus Student 3,386 PointsYou are the man! great example. now its much clearer.
CreativeGvc B
Courses Plus Student 3,386 PointsCreativeGvc B
Courses Plus Student 3,386 Pointsaha, Can you please give an easy example?
Thanks again!
Steven Parker
243,318 PointsSteven Parker
243,318 PointsSure here's one:
The setTimeout function is passed a callback function and a time, in this example 3000ms or 3 seconds. Then, an alert is called separately.
If you run this, you will see the "now" alert right away, even though it it called after the setTimeout. Then, 3 seconds later, you will see the "later" alert when the callback function gets executed.