Cheat Sheet

This cheat sheet contains important takeaways that lead up to section two.

1. Getting Started

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• class: contains all of your code.

• main(): entry point of your app.

• javac <file-name>.java: compiles your code.

• java <file-name>: runs the compiled code.

2. Variables

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Data types

There are 6 main data types (we didn't cover boolean yet).

long can store very big numbers. But, int is faster and takes less memory.

Operators

Scanner

nextLine(): scans for a String value.

nextDouble(): scans for a double value.

nextLong(): scans for a long value.

nextInt(): scans for an int value.

Coding Pitfalls

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• Put math operations in brackets if you wish to embed them inside a String.

  • "Example String " + (10 - 2) + " Example String " ;

• Trap: Putting nextLine() ahead of nextInt(), nextDouble(), nextLong(), or next().

  • Solution: add a throwaway nextLine() before the real nextLine().

**The reason this happens will be covered in the lesson: Delimiters.

Good coding habits

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• class: CamelCase.

• variable: lowerCamelCase.

Tips and tricks

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Terminal

• Use the up key to run previous terminal commands.

• Write clear to clear the terminal output.

• Press the tab key for auto-complete.

Escape characters

• \n adds a new line of space.

• \t adds a new tab of space.

Shortcut keys

• Use CMD/Ctrl+/ to comment a highlighted piece of code.