Hello World
println("Hello, World!")main.jl
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Julia 1.12.6Readymain.jlLn 1, Col 1Spaces: 4UTF-8
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main.jl · output appears here
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Julia is a high-level, high-performance language for technical and scientific computing, created by Jeff Bezanson, Stefan Karpinski, Viral B. Shah, and Alan Edelman and first released publicly in 2012. It uses a just-in-time compiler built on LLVM to deliver C-like speed while keeping the convenience of a dynamic language with optional type annotations and an interactive REPL.
Julia's design centers on multiple dispatch, where functions specialize on the types of all arguments, enabling expressive and fast generic code. It excels at numerical analysis, machine learning, data science, and simulation, and it can call C and Fortran libraries directly. A rich package ecosystem and built-in support for parallelism and metaprogramming make it popular in research and engineering.
main.jl is the entry point for each run.
Use the Input panel to pipe standard input to your program when it needs data.
Run sends your code to a fresh hosted runtime and streams the result into the output panel.
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println("Hello, World!")name = readline()
println("Hello, $name!")for x in [1, 2, 3, 4]
println(x^2)
endfunction add(a, b)
return a + b
end
println(add(2, 3))ages = Dict("alice" => 30, "bob" => 25)
ages["carol"] = 28
for (name, age) in ages
println("$name is $age")
endarea(r::Float64) = 3.14159 * r^2
area(w::Float64, h::Float64) = w * h
println(area(2.0))
println(area(3.0, 4.0))squares = [i^2 for i in 1:5]
println(squares)
v = [1.0, 4.0, 9.0]
println(sqrt.(v))
evens = filter(iseven, 1:10)
println(collect(evens))function safe_div(a, b)
if b == 0
throw(DivideError())
end
return a / b
end
try
println(safe_div(10, 0))
catch e
println("Caught: ", e)
endstruct Point
x::Float64
y::Float64
end
dist(p::Point) = sqrt(p.x^2 + p.y^2)
p = Point(3.0, 4.0)
println(dist(p))nums = 1:10
println(map(x -> x * 2, nums))
println(filter(isodd, nums))
println(reduce(+, nums))
println(sum(x^2 for x in nums))The editor uses Monaco, the engine behind VS Code, with language-aware editing tools and familiar keyboard controls.
Type or paste your code into the editor, then click Run (or press Ctrl/Cmd + Enter) to execute it.
Output streams into the console panel, including runtime errors, exit status, and execution time.
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Julia is one of 46 single-file compiler scratchpads. Each run submits only main.jl; local sibling-file imports are not enabled.
Linked-project languages (23): Node.js, TypeScript, Deno, Python, C, Go, Dart, Swift, Rust, Ruby, PHP, Java, Kotlin, C++, C#, Nim, Crystal, Haxe, Zig, Scala, D, Bun, Objective-C.
Single-file scratchpads (46): Matplotlib, NumPy, pandas, Haskell, Clojure, Perl, Lua, Tcl, jq, Raku, Elixir, Bash, Zsh, Nushell, R, Assembly (NASM), Julia, Octave, Groovy, PowerShell, Visual Basic .NET, Odin, Pascal, Lisp, Erlang, CoffeeScript, COBOL, BASIC, V, Racket, OCaml, Prolog, AWK, Emacs Lisp, Emojicode, Forth, F#, Fortran, Assembly (NASM64), Solidity, Mojo, Ada, WASM (WAT), Gleam, Shell Script (sh), Scheme.
Download file exports the active Julia source file.