Hash Tables & JavaScript Objects

Why is a prime number used as the hash table size?

class HashTable {
  constructor(size = 53) {
    this.keyMap = new Array(size);
  }
  
  _hash(key) {
    let total = 0;
    const WEIRD_PRIME = 31;
    for (let i = 0; i < Math.min(key.length, 100); i++) {
      total = (total * WEIRD_PRIME + key.charCodeAt(i)) % this.keyMap.length;
    }
    return total;
  }
}

It's faster to compute
It reduces memory usage
It minimizes collisions
Prime number size reduces collisions because: 1) Helps distribute keys more evenly across buckets, 2) Reduces patterns in hash distribution, 3) Prime numbers have no common factors except 1, 4) Improves hash function distribution properties, 5) Particularly effective with multiplication-based hashing, 6) Standard practice in hash table implementation, 7) Minimizes clustering of values, 8) Critical for maintaining O(1) average case performance.
It improves search speed

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