Lesson 44 of 55
8 mins readFormatted Strings: string.format()
In Plain English
`string.format(fmt, ...)` formats strings using standard ANSI C `printf` directives: `%s` (strings), `%d` (integers), `%f` (floats), `%x` (hexadecimal), and `%q` (quoted strings).
Deep Dive: How It Works
%d / %i: Format decimal integers.
%s: Format any string or value.
%.2f: Format float to 2 decimal places.
%04d: Zero-pad an integer to 4 digits width.
%q: Formats string safely with quotes and escapes for code generation.
Core Rules to Remember
printf Compatibility: Standard specifiers for precision, padding, and type formatting.
Zero-Padding and Precision: `%02d` for dates and `%.2f` for currency amounts.
Live Interactive Example
Hit Run Code to see it liveFormatting Strings with string.format
Python 3.12
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Output Console
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How it works: string.format aligned strings, zero-padded the ID, and rounded balance to 2 decimals.
Your Turn: Micro Challenge
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Micro Exercise
Format Endpoint and Port
- Declare `local host = "api.zen"` and `local port = 443`.
- Format with `string.format("Endpoint: https://%s:%d", host, port)` and print it.
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Sandbox Output
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