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mediumMachine Coding

Build a Calculator

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01

Understand the problem

Build a calculator supporting chained arithmetic operations.

ReactStateLogic
02

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Sketch your approach before reading the solution — that's what interviews test.

Nudge consolestandby

Stuck? Beam a request up — the console returns a conceptual nudge that guides your logic without spoiling the implementation.

03

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Building a Calculator in React

Mental model: Model the calculator as a tiny state machine: the current display, the stored operand, the pending operator, and a flag for whether the next digit starts a fresh number. Each button is an event that transitions this state. Keeping these four fields explicit avo

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04

React solution

Complete solutionRun Playground
import React from 'react';
import Calculator from './src/Calculator';

export default function App() {
  return (
    <div style={{ fontFamily: 'sans-serif', padding: 20 }}>
      <h1>Calculator Demo</h1>
      <Calculator />
    </div>
  );
}
05

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Transmission complete // awaiting log

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Dossier 62 of 87 decoded in the Frontend Machine Coding track. One more won't hurt.

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