Lesson 16 of 55
9 mins readGeneric for & ipairs() Array Iteration
In Plain English
`ipairs(table)` is an iterator function tailored for sequences (integer keys `1, 2, ... N`). It yields `(index, value)` pairs and stops at the first `nil` element.
Deep Dive: How It Works
1-Based Indexing: Lua array sequences start at index 1.
ipairs Behavior: Iterates `t[1], t[2], ...` consecutively until `t[i]` is nil.
Fast Sequential Scanning: Preferred iterator when table is used as an ordered list.
Core Rules to Remember
ipairs() for Arrays: Iterates numeric index-value pairs in consecutive 1..N order.
Stops at Nil: Stops immediately if it encounters a nil entry in the sequence.
Live Interactive Example
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Python 3.12
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Output Console
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How it works: ipairs yielded 1-based indices 1, 2, 3, 4 with corresponding values.
Your Turn: Micro Challenge
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Micro Exercise
Find Index of Target Item
- Declare `local items = { "apple", "banana", "cherry" }`.
- Loop with `ipairs(items)`. If `name == "banana"`, print `"Found banana at index " .. index`.
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Sandbox Output
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