What is array.includes in TypeScript?
Overview
TypeScript is similar to JavaScript in all ramifications. It is the superset of JavaScript. The only difference is that with TypeScript, we can do additional syntax, quick catching, handling of bugs, and so on. TypeScript runs wherever JavaScript runs.
In TypeScript, we can use the includes() method of an array to check if an array includes a certain element or value.
Syntax
array.includes(element)
The syntax for the includes() method in TypeScript
Parameter
element: This is the element we want to check to see if it is a member of the array.
Return value
If the array includes the specified element, then true is returned. Otherwise, it returns false.
Example
Let's look at the code below:
// create arrays in TypeScriptlet names: string[] = ["Theodore", "James", "Peter", "Amaka"]let numbers : Array<number>;numbers = [12, 34, 5, 0.9]let cars : Array<string> = ["Porsche", "Toyota", "Lexus"]let randomValues : Array<string | number | boolean> = ["one",1, "two", 2, 56, true]// check if array include some particular elementsconsole.log(names.includes("Theodore"))console.log(numbers.includes(10))console.log(cars.includes("Lexus"))console.log(randomValues.includes(false))
Explanation
- Lines 2 to 6: We create some arrays in TypeScript.
- Lines 9 to 12: We use the
includes()method of an array object to check if some elements are members of anarray. Then, we print the results to the console.