A practical introduction to Pascal programming language - GIARA

Iterative constructionsProgram 46: Exercise 3.8program c03e08;vara,b,i:integer;beginwrite(’Please input the first integer: ’);readln(a);write(’Please input the second integer: ’);readln(b);for i:=b downto a doif (i mod 2 =1) thenwrite(i,’ ’);writeln;(* Jumping the line *)for i:=a to b doif (i mod 2 =0) thenwrite(i,’ ’);writelnend.⊡3.4.2 Computing with sequencesThe exercises on sequences are based on the analysis of a series of numbers or characters. Wenever know in advance how many elements the sequence will have, so while and repeat arethe mainstream options to handle the iteration. Moreover, the program is required to capturesome information about the elements of the sequence, so that we need to mantain some kindof data about what we have seen so far, but at the same time having the ability to modify thatinformation depending upon the elements in the sequence.Exercise 3.9. Write a program that demands the user for as many characters as necessary untilthe user inputs the same character 2 times in a row.□Now we don’t have any idea of how many attempts it will take the user to satisfy thecondition. Hence, we use a while structure. In this exercise we use the variable b to save thelast value, while the one before the last one is stored in a. In this way, each time the user inputs anew number, a is updated (taking the value in b), while b stores the new one.⊡Program 47: Exercise 3.9program c03e09;vara,b:char;beginwrite(’Please input a char and press enter: ’);readln(a);write(’Please input the second char and press enter: ’);readln(b);while (ab) dobegina:=b;write(’Please another char and press enter: ’);readln(b)endend.45