Pseudocode

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Pseudocode is a high-level language which is used to define algorithms for data manipulation. Pseudocode is machine-independent and consists of simple instructions in a human language. Although there is no formal syntax, it is a useful way of outlining the desired data flow in the early stages of development.

Conventions

The 2014 Computer Science Guide defines a set of rules or conventions governing the coding style of pseudocode. Please note that, for historical reasons, some legacy examples on this wiki may not conform to these conventions. The current conventions can be downloaded as a PDF file from the foot of the page and important highlights are listed here.

  • Variable names are all capitals, for example, CITY
  • Pseudocode keywords are lower case, for example, loop, if ...
  • Method names are mixed case, for example, getRecord
  • Methods are invoked using the “dot notation” used in Java, C++, C#, and similar languages, for example, BIGARRAY.binarySearch( 27 )

Variable names

These will be provided and comments // used, for example:

N = 5 // the number of items in the array
SCOREHISTORY.getExam( NUM ) // get the student’s score on exam NUM

Assigning values

Values will be assigned using = , for example:

N = 5 // indicates the array has 5 data items
VALUE[0] = 7 // assigns the first data item in the array a value of 7

Output

Output—this term is sufficient to indicate the data is output to a printer, screen, for example:

output COUNT // display the count on the screen

Example algorithm

MAX = 0
MIN = 999
COUNT = 0
repeat 
    input TEMP
    if TEMP > MAX 
        then MAX = TEMP
    end if
 
    if TEMP < MIN 
        then MIN = TEMP
    end if
 
    COUNT = COUNT + 1
until COUNT = 100
output "The maximum temperature is " MAX " and the minimum is " MIN


For... next loop

MAX = 0
MIN = 999
 
for COUNT = 1 to 100
    input  TEMP
    if TEMP > MAX 
        then MAX = TEMP
    end if
 
    if TEMP < MIN 
        then MIN = TEMP
    end if
next COUNT
output "The maximum temperature is " MAX " and the minimum is " MIN