CODEWITHSUNDEEP
typescript
Virus
Virus

Reputation: 9

Can someone help me describe this typescript?

for (let i = 0; i < 10; i++) {
  setTimeout(function() {
    console.log(i);
  }, 100 * i);
}

When you run it: 0 1 2 3 4 5 6 7 8 9 But I cannot understand how it is working like we are multiplying i with 100??

Upvotes: 0

Views: 49

Answers (4)

Virus
Virus

Reputation: 9

Thanks for Help guys I am a newbie so I was not understanding it right

settimeout(function, parameter)

for (let i = 0; i < 10; i++) {
    setTimeout(function() {
      console.log(i);
    }, 100 * i);
  }

when we are executing it the value of i doesn't change after multiplying by hundred but just gives a 100ms delay in the output and every it increases by 100ms. And at the end the delay is 900ms.

Upvotes: 0

Abhijit
Abhijit

Reputation: 13

The For loop is calling the setTimeout() function total 10 times

So if simplified it can be written as follows...

setTimeout(function() { console.log(0); }, 0); # when i=0

setTimeout(function() { console.log(1); }, 100); # when i=1

setTimeout(function() { console.log(2); }, 200); # when i=2

setTimeout(function() { console.log(3); }, 300); # when i=3

and so on...

So whats happening is for each number in range of 0 to 9, setTimeout function sets the console.log() method for every interval of 100 ms. Try replacing that 100 to 1000 and you will see that the numbers are printed in a one second delay.

If you remove the i multiplied with 100 and just keep a specific value (like only 100) it will seem like all the numbers are printed at the same time after that value of interval.

Upvotes: 0

FZs
FZs

Reputation: 18619

i is going from 0 to 9, and in each iteration, it sets a timeout to i times 100.

That is, you end up with ten timeouts set for 0ms (0 * 100), 100ms (1 * 100), 200ms (2 * 100), and so on until 900ms (9 * 100).

i | i * 100 | delay
--+---------+------
0 | 0 * 100 |   0ms
1 | 1 * 100 | 100ms
2 | 2 * 100 | 200ms
3 | 3 * 100 | 300ms
4 | 4 * 100 | 400ms
5 | 5 * 100 | 500ms
6 | 6 * 100 | 600ms
7 | 7 * 100 | 700ms
8 | 8 * 100 | 800ms
9 | 9 * 100 | 900ms

Upvotes: 0

maha
maha

Reputation: 643

The setTimeout() method calls a function or evaluates an expression after a specified number of milliseconds.

so for the first loop, you have a delay of i*100=0, then the delay became 100 then 200 and so on, so the code logs i every time, but with different delays.

Upvotes: 1

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