foundation studies course m.montebello arrays foundation studies course

Foundation Studies Course M.Montebello

Arrays

Foundation Studies Course


Introduction

An array is a structure which holds many variables, all of the same data type.

The array consists of so many elements, each element of the array capable of storing one piece of data (ie, a variable).


Definition

An array is defined as follows:array_name = ARRAY [lower..upper] of data_type;

Lower and Upper define the boundaries for the array.

Data_type is the type of variable which the array will store, eg, type int, char etc.


Declaring Arrays

A typical declaration follows:VAR

marks = ARRAY [1..20] of integer;

This creates a definition for an array of integers called marks, which has 20 separate locations numbered from 1 to 20. Each of these positions (called an element), holds a single integer.


Assigning ValuesTo assign a value to an element of an array, use marks[2] := 10; This assigns the integer value 10 to element 2 of the

marks array. The value or element number (actually its called an index) is placed inside the square brackets.

To assign the value stored in an element of an array to a variable, use:

Var total:integer;

total := marks[1]+marks[2]+ … + marks[10]; This takes the integer stored in element 1 to 10 of the

array marks, and makes the integer total equal to it.


Exampleprogram Simple;

var name : string; maths,english,maltese,total: integer; average: real;

begin Write('Enter name of student ');

readln(names);

write('Enter marks for Maths --> '); readln(maths);

write('Enter marks for English --> '); readln(english);

write('Enter marks for Maltese --> '); readln(maltese);

total:= maths + english + maltese;

average:=total/3;end.


Exampleprogram Simple_Arrays;

var index : integer; names : array [1..10] of string; maths,english,maltese,total: array [1..10] of integer; average: array [1..10] of real;

begin for index := 1 to 10 do begin Write('Enter name of student ',Index,': '); readln(names[index]);

write('Enter marks for Maths --> '); readln(maths[index]);

write('Enter marks for English --> '); readln(english[index]);

write('Enter marks for Maltese --> '); readln(maltese[index]);

total[index]:= maths[index] + english[index] + maltese[index];

average[index]:=total[index]/3; end;end.


Lab

In order to store the telephone numbers of his friends, a programmer decided to make use of two 1-dimensional arrays to store the names and the corresponding phone numbers.

Garfield Asterix Taz … 79312444 99453552 79266262…

Write a short program to enter and store up to fifty names and telephone numbers. Ensure that the exact variable declarations are made as well as the correct program syntax in general is used.

foundation studies course m.montebello arrays foundation studies course

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