Programming > Structured Text > Concepts

Definition

An ARRAY is a fixed-size data structure that stores a sequential collection of elements of the same type in memory.

<variable> : ARRAY [<dimension>] OF <data type> := <inicialization>

The dimension of an ARRAY is determined by the range between the smallest and largest index, while the initialization of its elements is optional.

Example 1

The example below demonstrates the creation of an ARRAY and the assignment of one of its values to a variable.

VAR

arraySrc : ARRAY[0..2] OF USINT := [11, 22, 33];

varDst : USINT;

END_VAR

varDst := arraySrc[1];

At the end of the execution of the example code, the value of varDst should be 22.

Example 2

The example below illustrates the combination of the concepts of ARRAY, indexed variable and FOR loop to copy the values from one array to another.

VAR

arraySrc : ARRAY[0..2] OF USINT := [11, 22, 33];

arrayDst : ARRAY[0..2] OF USINT;

i : USINT;

END_VAR

FOR i := 0 TO 2 BY 1 DO

arrayDst[i] := arraySrc[i];

END_FOR