Loops

Loops run several times.

While loop

The while loop iterates as long as a condition is true.

let i = 0;
while (i < 9) {
  console.log('This piece of code ran. i equals: ' + i);
  i++;
}

Do...while loop

The do...while loop iterates as long as a condition is true. The difference between the while loop and do...while loop is the statement is executed once before the condition is checked.

let i = 0;
do {
  console.log('This piece of code ran. i equals: ' + i);
  i++;
} while (i < 9)

For loop

The for loop has a concise syntax. In between the parentheses there are three things that happen: a variable is declared, the condition is checked, and finally a change is made to the variable (this happens each time after the code within the code block is run).

for (let i = 0; i < 9; i++) {
  console.log('This piece of code ran. i equals: ' + i); 
}