Programming Concepts

CIE pseudocode supports the standard arithmetic operators, plus two functions specific to integer division.

CIE pseudocode uses these operators: +, -, *, / and the exponentiation operator ^, plus the two integer-division operations DIV and MOD, which are written as function calls: DIV(a, b) and MOD(a, b). The ^ operator raises a number to a power (for example 2 ^ 3 = 8, and X ^ 3 for "X cubed").

DIV: integer division

DIV(a, b) returns the whole-number part of a divided by b, throwing away any remainder.

DIV(17, 5) returns 3      // 17 ÷ 5 = 3 remainder 2
DIV(20, 4) returns 5      // 20 ÷ 4 = 5 exactly
DIV(9, 2) returns 4       // 9 ÷ 2 = 4 remainder 1

Useful for splitting things into equal groups: "how many full minutes are in 130 seconds?" → DIV(130, 60) returns 2.

MOD: remainder

MOD(a, b) returns the remainder after a is divided by b.

MOD(17, 5) returns 2      // 17 ÷ 5 = 3 remainder 2
MOD(20, 4) returns 0      // 20 ÷ 4 = 5 remainder 0
MOD(9, 2) returns 1       // 9 ÷ 2 = 4 remainder 1

Useful for a classic check: "is a number divisible by 2?" → MOD(Number, 2) = 0 is true for even numbers.

ROUND: rounding to a number of decimal places

ROUND(value, places) returns value rounded to places decimal places.

ROUND(3.14159, 2) returns 3.14   // two decimal places
ROUND(8.6, 0) returns 9          // zero decimal places: nearest whole number

value should be a real number and places a whole number. ROUND is useful for tidying up money or measurements before they are output.

RANDOM(): a random number

RANDOM() returns a random real number between 0 and 1 inclusive. It takes no arguments.

To get a random whole number in a range, scale the result and round it. For example, a random whole number from 0 to 6 is ROUND(RANDOM() * 6, 0). RANDOM() is the standard way to add chance to a program, such as rolling a dice or shuffling.