VARIABLES EN TURBO PASCAL SERIES

Each time we go through the center of the loop we tell it to print out one of the 64 variables in the Checkerboard matrix with the indices Index and Count defining which of the variables to write each time. The next section of the program does just that, by using another doubly nested loop, with a Write statement in the center.

Since the value of Checkerboard is now available, it is used to define some values to be used for the variable Value in line 12 of the program.ДЄfter defining all of those variables, and you should understand that we have defined a total of 128 variables in the double loop, 64 of Checkerboard and 64 of Value, they can be printed out. The assigned value has no real meaning other than to illustrate to you how it is done. The variable Checkerboard is subscripted by both of the loop indices and each of the 64 variables is assigned a value as a function of the indices. The two loop indices can therefore be used as subscripts of the defined array variables. Examining the program will reveal two loops, one nested within the other, and both ranging in value from 1 to 8. To use either of the two variables in a program, we must add two subscripts to the variable name to tell the program which element of the 64 we desire to use. Another way to achieve the same end is to define the double array as in the next line of the program where Value is defined as a total of 64 elements. This is called a doubly subscripted array and it can be envisioned in exactly the same manner as a real checker board, an 8 by 8 matrix. The variable Checkerboard is actually composed of 8 elements, each of which is 8 elements, leading to a total of 64 elements, each of which is a simple integer variable. You will see that Checkerboard is defined as an array from 1 to 8, but instead of it being a simple data type, it is itself another array from 1 to 8 of type integer. Compile and run this program.ДЄfter understanding the above example program, load the program to see the next level of complexity of arrays. Keep in mind that the array is actually composed of 12 different integer type variables that can be used in any way that it is legal to use any other integer type variable. Review this material and this program as long as needed to fully understand it, as it is very important. Note carefully that, although the subscripts are limited to 1 through 12, the values stored in each of the 12 variables are limited only by the range of integers, namely -32768 to 32767. With known values stored in the array, a header is now printed and the list of values contained in the array is printed. Any integer values could be used, this was only a convenient way to set the values to some well defined numbers.

VARIABLES EN TURBO PASCAL SERIES

As Index is varied from 1 to 12, the range of the subscripts of the variable Automobile, the 12 variables are set to the series of values 11 to 22. The subscript moreover, must be of the type used in the definition and it must be within the range defined or it will be construed as an error. Each time one of the variables is used, it must have the subscript since the subscript is now part of the variable name. In using the elements of the array in a program, each of the elements of the array are required to be used in exactly the same manner as any simple variable having the same type. The array definition given in line 5 is the standard definition for an array, namely a variable name, followed by a colon and the reserved word array, with the range of the array given in square brackets followed by another reserved word of and finally the type of variable for each element of the array. The square braces are used in Pascal to denote a subscript for an array variable. The variable Automobiles is defined as an integer variable but in addition, it is defined to have twelve different integer variables, namely Automobile, Automobile, Automobile. Display the Pascal program ARRAYS.PAS and notice line 5 starting with the word Automobiles. Let's go directly to an example to see what an array looks like. One of the most useful Pascal data structures is the array, which is, in the simplest terms, a group of 2 or more identical terms, all having the same type. Having covered nearly all of the programming statements, we must now go back and fill in some gaps in our data definition and look at the array in particular. At the beginning of this tutorial we said that a computer program is composed of data and executable statements to operate on that data.

Variables en turbo pascal