How to find the Total Number of Elements in an Array in TypeScript ?

In TypeScript, arrays are a common data structure used to store collections of elements. You can store multiple elements of different or the same data type inside them by explicitly typing.

The below methods can be used to accomplish this task:

Using the length property

The length property is used to get the length or size of an array. It can be used to get the total number of elements stored in the array.

Syntax:

array.length

Example: The below code implements length property to find total number of elements in an array.

const array: number[] = 
    [1, 2, 3, 4, 5];
const lengthUsingLengthProperty: number = 
    array.length;
console.log("Total number of elements: ", 
    lengthUsingLengthProperty);

Output:

Total number of elements: 5

Using the forEach method

The forEach method iterates over each element of the array thus incrementing a counter for each element and counting the number of elements in the array

Syntax:

array.forEach(() => {count++;} );

Example: The below code will explain the use of the forEach method to find number of elements in an array.

const array: number[] = [1, 2, 3, 4, 5];
let count: number = 0;
array.forEach(() => {
    count++;
}); 
console.log("Total number of elements: ", 
    count);

Output:

Total number of elements: 5

Using the reduce method

The reduce method accumulates the count of elements in the array by reducing the element in the array until array becomes empty.

Syntax:

const count = array.reduce((acc) => acc + 1, 0);

Example: The below code will explain the use of the reduce method to find total number of elements in an array.

const array: number[] = 
    [1, 2, 3, 4, 5];
const count: number = 
    array.reduce(
        (acc) => acc + 1, 0);
console.log("Total number of elements:", 
    count);

Output:

Total number of elements: 5

Using a for Loop

In this approach we Iterating through the array using a for loop, incrementing a counter for each element until the end of the array is reached, then returning the total count.

Example: In this example The function iterates through the array using a `for` loop, incrementing a count for each element, then returns the count. Finally, it logs the total count.

function getTotalElements(arr: any[]): number {
    let count = 0;
    for (let i = 0; i < arr.length; i++) {
        count++;
    }
    return count;
}

const array = [1, 2, 3, 4, 5];
const totalElements = getTotalElements(array);
console.log("Total number of elements:", totalElements);

Output:

Total number of elements:  5