For Loop

For loop sets condition variable initialization and modification on one line.

Syntax

for(initialization; condition; modification) { // Loop's body. }

initialization - sets variables used in the loop (like i = 0)

condition - Until when the cycle will keep on executing. Like i <= 10.

modification - could avoid infinite loops (like i++).

Basic Example

Let's have a program that prints each number from 1 to 10.

for (let i = 1; i <= 10; i++) { console.log(i); }

Output:

1 2 3 4 5 6 7 8 9 10

The initializationi = 1 performs first - before loop's iterations.

i++ executes in the end of every iteration.

Infinite loops

An infinite for-loop has a condition that's always true or it's unset.

Let's look at the following example

for (;;) { console.log(0); }

Output:

0 0 0 0 0 ...

Since condition is not specified the loop repeats infinitely.

There is more than 1 way of defining infinite loop.

for (let i = 1;;i++) { console.log(i); }

Output:

1 2 3 4 5 ...

In this case the only segment that's not specified is the condition therefore the cycle doesn't end.