while loops
The first loop we will discuss is the while loop. A while
loop executes a certain block of code as long as an expression evaluates to true
. The snippet below demonstrates the syntax of the while
loop:
while (condition) {
// code that gets executed as long as the condition is true
}
The while
loop will only be executed as long as the condition is true
, so if the condition is false
to begin with, the code inside will be skipped.
Here is a very simple example of a while
loop printing the numbers 0 to 10 (excluding 10) to the console:
let i = 0;
while (i < 10) {
console.log(i);
i++;
}
The output will be as follows:
1
2
3
4
5
6
7
8
9
These are the steps happening here:
- Create a variable,
i
, and set its value to zero - Start the
while
loop and check the condition that the value ofi
is smaller than 10 - Since the condition is true, the code logs
i
and increasesi
by 1 - The condition gets evaluated again; 1 is still...