How do I check whether an array contains a string in TypeScript?

Question

Currently I am using Angular 2.0. I have an array as follows:

var channelArray: Array = [\'one\', \'two\', \'three\'];

How ca

Answer 1

If your code is ES7 based:

channelArray.includes('three'); //will return true or false

If not, for example you are using IE with no babel transpile:

channelArray.indexOf('three') !== -1; //will return true or false

the indexOf method will return the position the element has into the array, because of that we use !== different from -1 if the needle is found at the first position.