What is hashing technique? Describe in brief.

Answer:

In general, in all searching techniques, search time is dependent on the number of items. Sequential search, binary search and all the search trees are totally dependent on number of items and many key comparisons are involved.

Hashing is a technique where search time is independent of the number of items or elements. In this technique a hash function is used to generate an address from a key. The hash function takes a key as input and returns the hash value of that key which is used as an address index in the array.

We can write hash function as follows
h(k)=a;

Where h is hash function, k is the key, a is the hash value of the key.

While choosing a hash function we should consider some important points.

• It should be easy to compute
• It should generate address with minimum collision.