One-dimensional arrays

One-dimensional array is a series of identical properties that are described by one identifier (array name) and sometimes they are also called vectors. Before we start working with an array, we need to tell the compiler to use the array. We have two ways to declare an array:

1. When declaring a variable to use the array 
   
2. Defining a new type 
   

When declaring a variable, we'll include data about array immediately after the variable name and a colon. The following is the word Array, which indicates the use of the array, the index type in square brackets, word of and a data type used in an array.

var

Array1: Array [1..10] of Integer;

Array2: Array [1..20] of String ;

We use the definition of a new type if we will work with the same type of array more than once in one program. When defining a new type we start with the word type, continue with the array name (at the beginning of the array name, the letter T is used as the default, which indicates the use of the type), followed by the equal sign, the word Array, the index type in square brackets, word of and data type used in the array. Then we have to declare the variable that will be used in the array.

type

TArray = Array [1..10] of Integer;

var

Array1, Array2: TArray;

When we declare an array, it is empty and contains no elements. These must be added to the array using the assignment command. We know that we use the assignment sign := to assign the value of some variable. For example, if you want an integer variable a to assign a value of 20, use the command a:= 20;. We will also do the same when filling the array.

Each array element represents a separate variable that the values ​​of that type can be assigned to or read from. Access to the individual elements of the array is possible thanks to the index. We suppose we create an array, which we call array. If we want to assign a value of 20 to the tenth element of our array, we will do it similar to assigning a variable value, but we will add the index value to square brackets after the array name, so the command will be as follows:

              Array1 [10]: = 20;

Now, we will demonstrate the operation of the array on specific examples. We define the array with ten elements. We can assign values ​​to elements in two ways:

1. Assigning a value to an element in the body of the procedure

Each of the elements we declare in the body of the procedure with using the index (Figure 111).

2. Assigning a value to an element when declaring a variable 

Each of the elements we declare when declaring the variable, where we write the individual elements in brackets in such order, in which they are to be assigned to each index (Figure 112).

Array elements can be written to the graphical area using the TextOut command. Since we have an array of integer elements, we must not forget to convert elements from integer data type to string. Regardless of which array definition method we use, the result will be the same (Figure 113).

This is how we have declared the value of the elements manually. However, we can also declare individual array elements by generating random values ​​using the Random function. Again, we define the array with ten random elements, which we then write to the graphical area (Figures 114 and 115).