Add some more shit

c.md

@@ -54,4 +54,75 @@ You can replace `gcc` with other compilers (e.g. `clang`, `tcc`, `g++` etc.), th
 - `-O3`: optimize for program speed, greatly speeds up your program (you can also use less aggressive `-O2` and `-O1`)
 - `-Os`: optimize for smaller program size
 - `-g`: include debug info, you want this so that debuggers can point to your source code
-- `-std=c99`: use the C99 standard
+- `-std=c99`: use the C99 standard
+
+## Cheatsheet
+
+It's pretty important you learn C, so here's a little cheat sheet for you.
+
+**data types** (just some):
+
+- **int**: signed integer, at least 16 bits (-32767 to 32767) but usually more
+- **unsigned int**: unsigned integer, at least 16 bit (0 to 65535) but usually more
+- **char**: smallest integer of at least 8 bits (1 byte, 256 values), besides others used for containing [ASCII](ascii.md) characters
+- **unsigned char**: like char but unsigned (0 to 255)
+- **float**: [floating point](float.md) number (usually 32 bit)
+- **double**: like float but higher precision (usually 64 bit)
+- **short**: smaller signed integer, at least 16 bits (−32767 to 32767)
+- **long**: bigger signed integer, at least 32 bits (-2147483647 to 2147483647)
+- **pointer**: memory address (size depends on platform), always tied to a specific type, e.g. a pointer to integer: `*int`, pointer to double: `*double` etc.
+- **array**: a sequence of values of some type, e.g. an array of 10 integers: `int[10]`
+- **struct**: structure of values of different types, e.g. `struct myStruct { int myInt; chat myChar; }`
+- note: header *stdint.h* contains fixed-width data types such as *uint32_t* etc.
+- note: there is no **string**, a string is an array of *char*s which must end with a value 0 (string terminator)
+- note: there is no real **bool** (actually it is in header *stdbool*), integers are used instead (0 = false, 1 = true)
+
+**branching aka if-then-else**:
+
+```
+if (CONDITION)
+{
+  // do something here
+}
+else // optional
+{
+  // do something else here
+}
+```
+
+**for loop** (repeat given number of times):
+
+```
+for (int i = 0; i < MAX; ++i)
+{
+  // do something here, you can use i
+}
+```
+
+**while loop** (repeat while CONDITION holds):
+
+```
+while (CONDITION)
+{
+  // do something here
+}
+```
+
+**do while loop** (same as *while* but CONDITION at the end):
+
+```
+do
+{
+  // do something here
+} while (CONDITION);
+```
+
+**function definition**:
+
+```
+RETURN_TYPE myFunction (TYPE1 param1, TYPE2, param2, ...)
+{ // return type can be void
+  // do something here
+}
+
+```