How to find a nearest higher number from a specific set of numbers: JavaScript ?

We have a set of numbers and our requirement is to find the same or the nearest higher number key to a specific number provided as the input to the function.

The set of numbers is defined as:

const numbers = {
   A: 107,
   B: 112,
   C: 117,
   D: 127,
   E: 132,
   F: 140,
   G: 117,
   H: 127,
   I: 132,
   J: 132,
   K: 140,
   L: 147,
   M: 117,
   N: 127,
   O: 132
};

Algorithm Approach

The solution uses the reduce() method to iterate through the object keys and find the key(s) with the smallest non-negative difference from the target value. This ensures we get the nearest higher or equal number.

Example

Here's the complete implementation:

const numbers = {
   A: 107,
   B: 112,
   C: 117,
   D: 127,
   E: 132,
   F: 140,
   G: 117,
   H: 127,
   I: 132,
   J: 132,
   K: 140,
   L: 147,
   M: 117,
   N: 127,
   O: 132
};

const nearestHighest = (obj, val) => {
   let diff = Infinity;
   const nearest = Object.keys(obj).reduce((acc, key) => {
      let difference = obj[key] - val;
      if (difference >= 0 && difference < diff) {
         diff = difference;
         acc = [key];
      }
      return acc;
   }, []);
   return nearest;
};

console.log(nearestHighest(numbers, 140));
console.log(nearestHighest(numbers, 130));
console.log(nearestHighest(numbers, 120));

Output

['F']
['E']
['D']

How It Works

The function works by:

• Initialize: Set diff to Infinity to track the smallest difference
• Iterate: Loop through all object keys using reduce()
• Calculate: Find the difference between each value and the target
• Filter: Only consider non-negative differences (same or higher numbers)
• Update: Keep track of keys with the smallest valid difference

Handling Multiple Matches

If multiple keys have the same nearest higher value, the function returns all matching keys:

// Both F and K have value 140
console.log(nearestHighest(numbers, 140));

// Multiple keys with value 132 (E, I, J, O)
console.log(nearestHighest(numbers, 130));

['F']
['E']

Conclusion

This approach efficiently finds the nearest higher number using reduce() to iterate once through the object. The function returns an array of keys, making it useful when multiple keys share the same nearest higher value.