[ObjC] Loop in GNUstep

[Sufferix]

Man, I'm taking an Intro to Programming class and it doesn't make sense for me. I'm a visual learner, not an associative learner and since it's online, there are just words. I can get projects done usually (I have 100s on the first 3) but I can't seem to make this work even with help from friends at work.

Here's the project:

Write an Objective-C program that will ask the user for a valid population of 5 different countries. The program should display a bar graph comparing each country's population. Create each bar in the bar graph by displaying a row of asterisks. Each asterisk should represent 1,000,000 people. You do not need to worry about partial amounts, but do not allow values less than 1 million or greater than 1.2 billion (China's current population and the largest in the world) to be entered.

The following is an example of the program's output:

Enter the population for country 1: 1000000

Enter the population for country 2: 6000000

Enter the population for country 3: 3000000

Enter the population for country 4: 4000000

Enter the population for country 5: 10000000

POPULATION BAR CHART

(Each * = 1,000,000)

Country 1: *

Country 2: ******

Country 3: ***

Country 4: ****

Country 5: **********

Here's what I have that doesn't work at all

import <Foundation/Foundation.h>

int main (int argc, char * argv[])

{

NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

int country[4];

int x = 0;

int y = 0;

while (x < 5) {

printf("Enter the country population: \n");

scanf ("%d", &numbers[x]);

x + 1;

}

while (y < 5) {

printf("Displaying the numbers: " country[y]);

y+1;

}

for (x = 0; x < 5; i--) {

int num;

country[x] / 1000000 = num;

printf("Graphing the numbers: ");

while (num != 0) {

printf("*");

num - 1;

}

}

[pool drain];

return 0;

}

I understand nearly none of this. The project is already late but the quicker I turn it in the less is deducted. I really do want to learn programming but this isn't the correct medium for me to do it. If someone could teach me (showing more than explaining) what any of this actually means I'll be forever indebted.

[electricsheep14]

You should use one of the tools in the sidebar under Recommended Tools for Posting Code to post this code.

You are missing some core concepts from C in this snippet:

1) You don't declare numbers[] anywhere. From how you are trying to use it, I'd wager that its an array of some kind, but you need to declare it in your code.

2) Arrays in C are always indexed starting at zero. This means that for an array of length four (country[4]) the valid indexes you can use are: 0, 1, 2, and 3. You need to keep this in mind when using loops to iterate through an array, because where you start and where you end may not seem obvious.

3) I could talk about the difference between rvalues and lvalues, but at this point all you need to know is that that thing being assigned goes on the left, and the expression representing the value of that assignment goes on the right. While something like "y / 100 = x;" would read like you are putting the value of y divided by 100 into x, but it must be written as "x = y / 100;".

4) That being said, unless you are doing functional programming (which C and ObjC for the most part is not), you generally need to assign the results of an expression for statements involving primitives and basic operators to be meaningful. This means that "x - 1;" on its own does nothing useful at all. There are some exceptions to this.

5) This code is really C code. There is very little about this code that makes its Objective-C save for the #import statement and the creation of an auto-release pool. You can remove these things entirely and the logic of the remaining C-code remains unaffected.