如何显示给定数组中两个相同数字的索引

Question

I'm trying to create a function with the parameters (number, target) that returns the index of two numbers in a given array that is equal to sum of the target. Here's the code so far:

   const twoSum = function (nums, target) {

    let num1;
    let num2;
    let index1;
    let index2;

    for(let i = 0;  i < nums.length; i++){
      
        num1 = nums[i];
        num2 = target - num1;
       
        if(nums.includes(num2){
            index1 = nums.indexOf(num2);
            index2 = nums.indexOf(num1);
        }
    
    }
    return [index1, index2];
}

The problem is; when the array consists of like numbers, it returns just the index of the first number twice eg twoSum([5,5,3], 10) returns [0,0] instead of [0,1]

Answer 1

I don't know exactly what you are looking for, but this will give you what you described.

const twoSum = function (nums, target) {

    let num1;
    let num2;
    let index1;
    let index2;

    for(let i = 0;  i < nums.length; i++) {
      
        num1 = nums[i];
        num2 = target - num1;
       
        if(nums.includes(num2)) {
            index1 = nums.indexOf(num1);
            if(num1 === num2) {
                index2 = nums.findIndex((num, i) => num === num2 && i != index1);
                if(index2 === -1) return -1; //returns -1 if no second number was found
            } else {
                index2 = nums.indexOf(num2); 
            }
            return [index1, index2]; 
        }
    
    }
}