Question

How to find a number in array that appears once in TypeScript

Answer 1

// indexOf(searchElement, fromIndex)
 
function get_single_number(arr: number[]) {
    for (let i: number = 0; i < arr.length; i++) {
        if (arr.indexOf(arr[i], arr.indexOf(arr[i]) + 1) === -1) {
            return arr[i];
        }    
    };
     
    return -1;
};
     
  
const arr: number[] = new Array(3, 2, 1, 2, 3, 3, 1, 0, 9, 7, 7, 9, 9); 
        
console.log(get_single_number(arr));
 
    
    
/*
run:
    
0
    
*/

 

70+ SQL courses for beginners and professionals