Question

How to prevent adding duplicates to an array in TypeScript

Answer 1

const arr = ['javascript', 'typescript', 'nodejs', 'php'];

const s = 'java';

if (!arr.includes(s)) {
  	arr.push(s);
}

console.log(arr); 

   
   
   
   
/*
run:
   
["javascript", "typescript", "nodejs", "php", "java"] 
   
*/

 

70+ SQL courses for beginners and professionals