JuliaLang/julia

Printf for complex numbers

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#58,617 opened on Jun 3, 2025

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 (4 comments) (0 reactions) (0 assignees)Julia (5,773 forks)batch import
complexdisplay and printingfeaturehelp wanted

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Description

Currently, @sprintf "%.2f" (1+2im) errors, but it would make sense for it to produce "1.00 + 2.00im" I think. Currently, printfing a complex number is not really convenient, requiring a manual split into real + complex, and keeping the format string in sync between them.

Contributor guide

Research direction
Examine the Printf module source in base/printf.jl, understand how format specifiers are processed, and add handling for complex numbers to format real and imaginary parts separately.
Tech stack
None
Domain
backend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-2 days
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
JuliaPrintf internals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
55