Scratch

Batch. A programming language that is simple and practical, and built directly for Windows. It can access computers over a network, or just make a fun, simple game.

Batch Tutorial by Sep

Chapter 0: Before we start.
Before we start, you should learn a little about batch, or MS-DOS.
When you write a file, all output will come up in a Command Prompt window, like this:

As you can see, it's not very good for full scale games, but it is still very useful.

Batch commands are easily written in any notebook software, like Notepad.
Batch is written line-by line, every line is a new command.

Chapter 1: The basics.

Commands to learn:
echo

Echo is probably the command you will use the most. It will print (write) the letters after it on the prompt window. At the beginning of a program,
you will most always put "@echo off" at the beginning of your program.
pause

Another great command that will wait for the user to press a key to continue. You can also use "pause>null" so the command doesn't display a message.


First Project!
Open up notepad, and paste or type this code.

@echo off
echo This is the first line.
echo.
echo The above line should be blank.
pause

Now, hit save, an d save it as "batch.bat" without the quotes.

Now, let's look at the code.

@echo off This stops the program from putting the file location before each line. Weird, huh?
echo This is the first line. This should print a line with the text "This is the first line."
echo. This works line the [Enter] or [Return] key. Don't put just "echo"
echo The line above should be blank. This should print a line with the text "The line above should be blank."
pause This should ask for the user to input a key, then the file should close.

Chapter 2: Variables and Linking

Commands to learn:
set _____ =

Set is used to create or set the value of a variable.You cannot make a good application without set.

%_____%

%% is not a command, but the symbol of a variable being called. If you set a variable, v, to 7, and echo %v%, the result will be "7".

+, -, /, *, and ^.

+,-,/,*, and ^ are all operators, like on scratch, that you can use to find results. You can add two numbers or variables this way. When using math, put /a before the variable name in set.

(string linking)

You can easily link strings together by  just putting a space. If you set the variable 'name' to SeptimusHeap, and put this code, "echo: My name is %name%" the result would be "My name is SeptimusHeap".

Name & Age
(Yeah, this sorta stinks...)

@echo off
set name=YOUR NAME
set age=AGE
echo Hello, %name%. You're %age% years old, right?
set /a ageinten=%age%+10
echo Just think, in 10 years, you'll be %ageinten%.
pause>null

Save it as a .bat file, and run it.

Now, let's explain the code.

@echo off This stops the program from putting the file location before each line.
set name=YOUR NAME This sets the name variable to whatever you put.
set age=AGE This sets the age variable to whatever you put.
echo Hello, %name%. You're %age% years old, right? This says hello, and says your name.
set /a ageinten=%age%+10 This figures out your age in 10 years.
echo Just think, in 10 years, you'll be %ageinten%. This shows it.
pause>null This pauses without a message.

Chapter 3: If... Else  Statements

Commands to learn:

if "__"=="__"( )

The basic if command. I know. Batch is wacky. This is how it would look:

if "%variable%"=="Hello world" (
    echo Hello, user!
)

if "__"=="__"( )else( )
An if... else statement. This is how it would look in a file:

if "%answer%"=="scorpion" (
    echo You got it right!
) else (
    echo Try again!
)

You can also nest ifs and elses, like so:

if "%answer%"=="bomb" (
    echo You got it right!
) else (
    if "%answer%"=="chuck norris" (
        echo O_O
    )
)

Sorry, no program yet!

Last edited by SeptimusHeap (2010-11-26 13:36:46)