This is a shell for a simple Calculator app, bootstrapped with Create React App.
Your task is to fill out the functionality based on the following requirements:
Initial state: The calculator should show "0" if nothing has been entered. The user cannot enter an operator first, but must start by entering a number.
Display: The display area shows the numbers and operators entered by the user, as well as the result of the calculation after the user clicks "=".
AC button: Clicking the AC button clears the calculator state and reset the display to "0".
Digit buttons: Used to enter numbers.
Decimal (".") button: Adds a decimal to a number, or begins a number that starts with "0.".
+/- button: Negates a number, adding or removing -
as needed. Ignored if the most recent entry is not a number.
Operator buttons: The %, +, -, X, and ÷ buttons are all considered operators. Clicking one of these buttons enters an operator. If two operator buttons are clicked in a row (e.g. first an "X" and then a "-"), the second operator will overwrite the first operator.
= button: Calculates and displays the result of the arithmetical expression that was entered by the user. All operators are executed in order, regardless of the operation being performed. The "%" operator is shorthand for dividing by 100.
In the project directory, you can run:
Runs the app in the development mode.
Open http://localhost:3000 to view it in your browser.
The page will reload when you make changes.
You may also see any lint errors in the console.
Launches the test runner in the interactive watch mode.
See the section about running tests for more information.
Builds the app for production to the build
folder.
It correctly bundles React in production mode and optimizes the build for the best performance.
The build is minified and the filenames include the hashes.
Your app is ready to be deployed!
See the section about deployment for more information.
Note: this is a one-way operation. Once you eject
, you can't go back!
If you aren't satisfied with the build tool and configuration choices, you can eject
at any time. This command will remove the single build dependency from your project.
Instead, it will copy all the configuration files and the transitive dependencies (webpack, Babel, ESLint, etc) right into your project so you have full control over them. All of the commands except eject
will still work, but they will point to the copied scripts so you can tweak them. At this point you're on your own.
You don't have to ever use eject
. The curated feature set is suitable for small and middle deployments, and you shouldn't feel obligated to use this feature. However we understand that this tool wouldn't be useful if you couldn't customize it when you are ready for it.
You can learn more in the Create React App documentation.
To learn React, check out the React documentation.
This section has moved here: https://facebook.github.io/create-react-app/docs/code-splitting
This section has moved here: https://facebook.github.io/create-react-app/docs/analyzing-the-bundle-size
This section has moved here: https://facebook.github.io/create-react-app/docs/making-a-progressive-web-app
This section has moved here: https://facebook.github.io/create-react-app/docs/advanced-configuration
This section has moved here: https://facebook.github.io/create-react-app/docs/deployment
This section has moved here: https://facebook.github.io/create-react-app/docs/troubleshooting#npm-run-build-fails-to-minify