Using Foreach in Typescript: A Helpful Guide

In this article, we'll explore how to use the `foreach` method in Typescript to iterate over an array and perform operations on each element.

When working with arrays in Typescript, it's often necessary to loop through each element and perform some action. This is where `foreach` comes in handy. The `foreach` method calls a function for each element in the array, making it easy to process each item individually.

Example Usage

Let's consider an example of how you might use `foreach` in Typescript. Suppose we have an array of objects and we want to extract all the elements that have a specific type:

```typescript

var friendArray = new Array();

for (let i in friendArray) {

if (friendArray'i'.type === 'FRIEND') {

console.log(friendArray'i');

}

```

This code uses a `for` loop to iterate over the elements of the array and checks each element's type. However, this approach can be cumbersome and error-prone.

Using `foreach`, we can simplify the process:

```typescript

var friendArray = new Array();

friendArray.forEach((element) => {

if (element.type === 'FRIEND') {

console.log(element);

}

});

```

In this example, we pass a callback function to `foreach` that is called for each element in the array. The callback function checks whether each element's type matches `'FRIEND'`, and logs it to the console if it does.

Implicit Any Type Error

When using `foreach` with an array of objects, you may encounter an error message indicating that a binding element has an implicitly any type:

```

error: Binding element 'type' implicitly has an 'any' type.

```

This error occurs because Typescript is unable to infer the type of the `type` property. To resolve this issue, we need to specify the type explicitly:

```typescript

var friendArray = new Array();

friendArray.forEach((element) => {

if (element.type === 'FRIEND') {

console.log(element);

}

});

```

In conclusion, `foreach` is a powerful method in Typescript that allows us to iterate over an array and perform operations on each element. By using `foreach`, we can simplify our code and avoid the pitfalls of manual looping. Whether you're working with GraphQL data or simply need to process an array of objects, `foreach` is an essential tool to have in your toolkit.

For each in typescript