Working with the TypeScript Spread Operator

What is the TypeScript Spread Operator?

The TypeScript spread operator is a powerful syntax feature that can be used to efficiently work with arrays and other collections. It allows you to quickly, and easily, spread values into new arrays or objects. The spread operator is denoted by three consecutive dots (“…”).

How to Use the TypeScript Spread Operator?

There are two primary use cases for the spread operator. The first is to quickly create copies of existing objects. The second is to quickly populate an array or object with values from another array or object.

Copying an Object

To quickly create a copy of an existing object using the spread operator, simply use the “…” syntax followed by the object you would like to copy and assign the result of this statement to a new variable. For example: let originalObject = {a: 1, b: 2}; let newObject = {...originalObject}; In this example, we have created a copy of the originalObject and assigned it to the newObject variable. Both originalObject and newObject will have the same properties and values.

Populating an Array/Object

To quickly populate an array or object with values from an existing array, simply use the “…” syntax followed by the array you would like to copy the values from. For example: let originalArray = [1, 2, 3]; let newArray = [0,...originalArray]; In this example, we have created a new array with the value 0 at the beginning and the values from originalArray at the end. The newArray will contain the values 0, 1, 2, and 3. The spread operator can also be used to quickly populate an object with values from an existing object. For example: let originalObject = {a: 1, b: 2}; let newObject = {c: 3, ...originalObject}; In this example, we have created a new object with the value c set to 3 and all the values from originalObject included. The newObject will contain the values a: 1, b: 2, and c: 3.

Conclusion

The TypeScript Spread Operator is a powerful tool that can be used to quickly and easily copy objects and populate arrays and objects with values from existing collections. It can be used to streamline and simplify your code, so it is worth exploring in greater detail.