Indexed

Events and Logging

Events emit indexed logs to the blockchain that off-chain applications can efficiently query, providing a cheap way to record activity that smart contracts the…

Indexed File Processing (VSAM)

Understand how COBOL uses indexed files, typically backed by VSAM KSDS on mainframes, to perform fast random and sequential access by key.

Fenwick Trees (Binary Indexed Trees)

A compact array-based structure using the lowbit trick to compute prefix sums and point updates in O(log n).

Indexed and Associative Arrays

Understand PHP's single array type used for both ordered lists and key-value maps, including creation, iteration, and common manipulation patterns.

Arrays in Bash

Learn how to create, index, and iterate indexed and associative arrays in Bash, and how to use them to write scripts that handle lists of data correctly.