Declare an array in TypeScript

by

Here are the different ways in which you can create an array of booleans in typescript:

let arr1: boolean[] = [];
let arr2: boolean[] = new Array();
let arr3: boolean[] = Array();

let arr4: Array<boolean> = [];
let arr5: Array<boolean> = new Array();
let arr6: Array<boolean> = Array();

let arr7 = [] as boolean[];
let arr8 = new Array() as Array<boolean>;
let arr9 = Array() as boolean[];

let arr10 = <boolean[]>[];
let arr11 = <Array<boolean>> new Array();
let arr12 = <boolean[]> Array();

let arr13 = new Array<boolean>();
let arr14 = Array<boolean>();

You can access them using the index:

console.log(arr[5]);

and you add elements using push:

arr.push(true);

When creating the array you can supply the initial values:

let arr1: boolean[] = [true, false];
let arr2: boolean[] = new Array(true, false);

More Related Contents:

  1. How to convert an array of objects to object with key value pairs
  2. Angular2 component’s “this” is undefined when executing callback function
  3. Get list of duplicate objects in an array of objects
  4. How can I use optional chaining with arrays and functions?
  5. spread operator vs array.concat()
  6. How can I loop through enum values for display in radio buttons? [duplicate]
  7. TypeScript enum to object array
  8. flattening the nested object in javascript
  9. Custom/Modified 'Fibonacci' Number sequence
  10. Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array
  11. How to sort an array of objects by multiple fields?
  12. What is the difference between ( for… in ) and ( for… of ) statements?
  13. How to add same elements to javascript array n times
  14. forEach on querySelectorAll not working in recent Microsoft browsers
  15. How can I convert the “arguments” object to an array in JavaScript?
  16. forEach on array of undefined created by Array constructor
  17. Return index of greatest value in an array
  18. Backbone.js Empty Array Attribute
  19. angular ng-repeat in reverse
  20. Inject TypeORM repository into NestJS service for mock data testing
  21. Objects are not valid as a React child. If you meant to render a collection of children, use an array instead
  22. Split array into chunks of N length [duplicate]
  23. Convert ES6 Iterable to Array
  24. Push Object in Array [duplicate]
  25. Javascript array sort and unique
  26. How to sort array of objects based on a boolean property?
  27. Workaround for accessing class type arguments in static method in Typescript
  28. Finding all permutations of array elements as concatenated strings
  29. How to sort a JavaScript array of objects by nested object property?
  30. Filter array by string length in javascript [duplicate]

Leave a Comment