data types

• Data type

  The kind of data a variable contains, it can be character, string, integer, real or boolean
• Character

  The data type of a single character e.g. "A" or "$"
• String

  This data type stores a series of characters, e.g. "Zak", "MK44 5AB" or "123456789"
• Integer

  The data type of a whole number e.g. 5, 999 or -4
• Boolean

  This data type has only two values, TRUE and FALSE
• Real

  A data type also called floating point numbers, they have a decimal part, for example 1.5, 0.935 or the value of Pi
• Casting

  Changing the data type using a function such as STRING_TO_INT() or REAL_TO_STRING
• STRING_TO_INT('12')

  This AQA standard pseudo-code expression uses a casting function to change a string to an integer and results in the integer value 12
• REAL_TO_STRING(12.8)

  This AQA standard pseudo-code expression uses a casting function to change a real to a string and results in the string value "12.8"
• STRING_TO_REAL('12.8')

  This AQA standard pseudo-code expression uses a casting function to change a string to a real and results in the real value 12.8
• Comparison

  This type of operation always returns a boolean value, because it answers a question such as age > 18 or answer == "Yes"
• Arithmetic

  This type of operation returns either integer or real values because it performs a numeric calculation such as fare * 2.5 or sum(temps)
• Logic

  This type of operation always returns a boolean value (True or False) because it performs boolean operations on other boolean expressions