Data about each oceanographic reading is stored as a STRING variable named sensorLog in a research database.
The data string for a specific acoustic Doppler profiler reading is shown below:
ADCP-08B 348.5m 2026-04-12T14:35:02Z OK
Using 0-based indexing:
State the indexing expression (using the variable name sensorLog) for the first character of the ISO 8601 timestamp (2026-04-12T14:35:02Z).
State the indexing expression (using the variable name sensorLog) for the last character of the ISO 8601 timestamp (2026-04-12T14:35:02Z).
State the total number of characters (length) of the entire ISO 8601 timestamp substring.
44 exam-style questions on Edexcel GCSE Computer Science Data types and structures, covering Primitive and structured data types, Using variables and constants, and Manipulating strings. Each one has a worked solution and a mark scheme showing where the marks go.