Custom code dry run

Trace code line by line before you run it

Paste a short algorithm snippet and inspect the execution timeline, variables, console output, and data-structure snapshots. The tracer is intentionally static and safe: it explains control flow without executing arbitrary user code.

Code editor

Traces assignments, arrays, if branches, swap calls, and console.log output.

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1const numbers = [5, 2, 8, 1];

2let minIndex = 0;

3if (numbers[1] < numbers[minIndex]) {

4 minIndex = 1;

6swap(numbers, 0, minIndex);

7console.log(numbers);

Updated numbers to [5, 2, 8, 1].

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Variables

numbers[5, 2, 8, 1]

Console output

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