GCSE Link: 2.02 (Data Types)

This definition is copied over from the page for GCSE:

The data type of a variable determines how its binary form in memory is interpreted.

The following table is similar to the one on the GCSE page.

Table 1 shows the seven main data types in C#.

Table 1

Name	Description	Example C# declaration
Integer	A whole number.	int minAge = 16;
Floating point (single precision)	A number with a decimal part, stored using 32 bits.	float height = 1.63f;
Floating point (double precision)	A number with a decimal part, stored using 64 bits.	double pi = 3.141592653589793;
Boolean	Either "true" or "false".	bool flag = false;
Character	A single Unicode character.	char currency = '£';
String	A sequence of characters.	String bestRevisionGuide = "CS.RN v2";
Date/Time	A date and time.	DateTime epoch = new DateTime(1970, 1, 1);

A pointer (or reference) stores the memory address of a variable.

They effectively "point to" where the data is being held, instead of storing it themselves.

Note: pointers don't exist in C# because they are deemed unsafe.

Because memory is assigned at runtime, the value of a pointer will always be different each time you run a program.

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How do we convert between data types in pseudocode?

INT_TO_STRING(123)     "123"
STRING_TO_INT("123")   123
REAL_TO_STRING(1.23)   "1.23"
STRING_TO_REAL("1.23") 1.23


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