Previous Post. Next Post. Related Posts. Programming Python. Python is one of the languages that is witnessing incredible growth and popularity year by year.
In ,…. Read More. A function is a program which is used perform certain specific task. Mainly, there are two types of…. Then do the same with elements 1 and 2, etc. The only output necessary for this program is the median value. Using the sorting program we developed this chapter, change it so that the numbers generated range between 1 and Change the original sorting program so that it generates items.
Change the original sorting program so that the list is sorted in descending order. Before we dive into subscripts this chapter, we'll give you theanswers to the problems at the end of chapter seven. Here is the program listingfor the random integers from 0 to 9 notice how we used blank lines to makeit a little easier to read :.
Notice that we used a different variable to represent each digit that couldbe generated, and the somewhat long series of IF THEN statements to assign thedigit to the appropriate variable. We will show you this program again later inthis chapter, but using subscripts. It will bring the program to less than halfof its current size. Also notice the size of our FOR NEXT loop. Ourindentation help us make sure that there is one of each.
Let's get to the coin tosses. Here is the version for the 0. Notice again our use of tabs and blank lines toenhance the readability:. Notice that we don't do any calculations to the random number, just check itsvalue. Here is the other method of converting the random number to either a 1 or At the end of chapter seven, we developed a program to find the average of alist of numbers, and then determine the distance of each element from theaverage.
As you recall, the program we developed wasn't too bad for tenelements, but then we wanted to find out for a list of elements! Thisrequires a program that is lines long and contains different variables. The subscript is placed in parenthesesafter the variable being subscripted. That may not seem too impressive, but thesubscript itself can be a variable, and can be as large as necessary! For ourfirst averaging program, we would need 10 numbers ranging from A 1 to A Inthe second example, we could store the numbers as A 1 to A In bothcases, the values are all stored in the variable A, and the subscript could begenerated with a FOR A variable that has its data stored in subscript form is called an array.
For example, a two- dimensional array would look likeA 1,2 , and a three-dimensional array would look like A 4,3,6. Let's can the chatter and get into some programming. Here is the first fingerexercise for this chapter:. This program does the same thing as the one in chapter 7, but takes 8 fewervariables. Go ahead and run the program. Now we'll adjust the program to use 20elements.
The green lines are the changed or new ones:. Now go ahead and run the program. What happened? Well, you get a'Subscript out of range' error! Why is that? It's because the computerneeds to have a separate memory location for each element of the array, andlarge arrays can take up a lot of memory.
The computer will automatically setaside ten 'slots' for each subscripted variable, since ten does nottake up too much memory. But what if we need, say, slots? How do we tell thecomputer to set aside the necessary memory locations?
We use the DIM command. DIM is short for Dimension. DIM tells the computer how much memory to reservefor an array. There is no harm in reserving more memory than is actually needed,provided you don't exceed the memory capacity of QBASIC. Here is what a DIMcommand looks like:. Kemeny and Thomas E. May 1, 1. The two math professors deeply believed that computer literacy would be essential in the years to come, and designed the languageits name stood for Beginners All Purpose Symbolic Instruction Codeto be as approachable as possible.
It worked at first at Dartmouth, then at other schools. In the 1. BASIC did as much as anything else to make them useful. Especially the multiple versions of the language produced by a small company named Microsoft. Thats when I was introduced to the language when I was in high school, I was more proficient in it than I was in written English, because it mattered more to me.
I happen to have been born less than a month before BASIC was, which may or may not have anything to do with my affinity for it.
BASIC wasnt designed to change the world. We were thinking only of Dartmouth, says Kurtz, its surviving co creator. Kemeny died in 1. We needed a language that could be taught to virtually all students and faculty without their having to take a course. Their brainchild quickly became the standard way that people everywhere learned to program computers, and remained so for many years. But thinking of its invention as a major moment only in the history of computer languages dramatically understates its significance.
In the mid 1. You used a keypunch to enter a program on cards, turned them over to a trained operator and then waited for a printout of the results, which might not arrive until the next day.
You told the computer to do something by typing words and math statements, and it did it, right away. We were thinking only of Dartmouth. Today, we expect computersand phones, and tablets and an array of other intelligent devicesto respond to our instructions and requests as fast as we can make them.
In many ways, that era of instant gratification began with what Kemeny and Kurtz created. Moreover, their work reached the public long before the equally vital breakthroughs of such 1. Douglas Engelbart, inventor of the mouse and other concepts still with us in modern user interfaces. You might assume that a programming language whose primary purpose was to help almost anybody become computer literate would be uncontroversialmaybe even universally beloved. Youd be wrong. BASIC always had its critics among serious computer science types, who accused it of promoting bad habits.
Even its creators became disgruntled with the variations on their original idea that proliferated in the 1. Nobody conspired to get rid of it no one factor explains its gradual disappearance from the scene.
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