Sparse Array

Definitions

1. An array in which most elements have the same default value (typically zero or undefined) and only the non-default entries are actually stored, using structures like hash maps or compressed row storage to save memory. Common in scientific computing, game engines (entity-component systems), and JavaScript (where deleting array elements creates holes).

   In plain English: An array that saves memory by only storing the entries that actually have values, skipping all the empty or zero slots.

   Example: "The 10-million-element matrix is 99.9% zeros, so we store it as a sparse array and use 1/1000th of the memory."

Related Terms

• Amortized Analysis
• Allocatable
• Broadcasting
• JSON Pointer
• Ring
• Weak Map
• Weak Set
• Array List