Javascript 查找数组中最相近的数

大概就是二分法去找，我这个是个简单例子

function findClosest(arr, target)
{
    console.log(arr[0].subt_nat_amount.value)
    let n = arr.length;
    if (target <= arr[0].subt_nat_amount.value)
        return arr[0].subt_nat_amount.value;
    if (target >= arr[n - 1].subt_nat_amount.value)
        return arr[n - 1];

    let i = 0, j = n, mid = 0;
    while (i < j)
    {
        mid = (i + j) / 2;

        if (arr[mid].subt_nat_amount.value == target)
            return arr[mid];
        if (target < arr[mid].subt_nat_amount.value)
        {
            if (mid > 0 && target > arr[mid - 1].subt_nat_amount.value)
                return getClosest(arr[mid - 1].subt_nat_amount.value,
                                arr[mid].subt_nat_amount.value, target);
            
            j = mid;            
        } else
        {
            if (mid < n - 1 && target < arr[mid + 1])
                return getClosest(arr[mid].subt_nat_amount.value,
                                arr[mid + 1].subt_nat_amount.value,
                                target);            
            i = mid + 1;
        }
    }

    return arr[mid];
}

function getClosest(val1, val2, target)
{
    if (target - val1 >= val2 - target)
        return val2;    
    else
        return val1;    
}

简单直白的：

const arr = [2, 42, 82, 122, 162, 202, 242, 282, 322, 362]
const goal = 100
const closest = arr.reduce((prev, curr) => {
  return (Math.abs(curr - goal) < Math.abs(prev - goal) ? curr : prev);
});
console.log(closest)