Different Types of Loops in Typescript(For, While)

for Loop

The for loop is used to execute a block of code a given number of times, which is specified by a condition.

Example

for (let i = 0; i < 3; i++) {

    console.log ("Serial Number" + i);

  }

Output

Serial Number0 Serial Number1 Serial Number2

for...of Loop:

This will be used with arrays,lists,tuples

Example

for (let i = 0; i < 3; i++) {

    console.log ("Serial Number" + i);

  }

  let arr = [10, 20, 30, 40];

  for (var val of arr) {

    console.log(val);

  }

Output

Serial Number0 Serial Number1 Serial Number2 10 20 30 40

for...in Loop

This can be used with an array, list, or tuple. The for...in loop iterates through a list or collection and returns an index on each iteration.

for (let i = 0; i < 3; i++) {

    console.log ("Serial Number" + i);

  }

  let arr = [10, 20, 30, 40];

  for (var val of arr) {

    console.log(val);

  }

  for (var index in arr) {

    console.log(index);

 

    console.log(arr[index]);

  }

Output

10 20 30 40 0 10 1 20 2 30 3 40

While Loop

The loop runs until the condition value is met.

Example

let i: number = 2;

while (i < 4) {

    console.log( "Serial Number." + i )

    i++;

}

Output

Serial Number.2 Serial Number.3

do..while loop

The do..while loop is similar to the while loop, except that the condition is given at the end of the loop. The do..while loop runs the block of code at least once before checking for the specified condition. For the rest of the iterations, it runs the block of code only if the specified condition is met.

Example

Syntax:

do {
// code block to be executed
}
while (condition expression);

let i: number = 2;
do {
    console.log("Serial Number." + i )
    i++;
} while ( i < 4)

Output

Serial Number.2 Serial Number.3