Programming Forums > Application Development > C++

peaceofpi · Jun 22nd, 2006, 2:25 PM

I mean, I'm not an idiot. But, I just can't keep up with a lot of lessons online. The one at cplusplus.com? Lost me. Anything on Google? Lost me.

I downloaded "Wrox - C++ tutorial.chm" and it's been pretty good to me, but now I'm lost again at arrays. Eventually all lessons seem to assume you know a lot.

Is there anything besides a real life book (next plan) anyone can recommend to me, that teaches C++, while..."talking slow"?

DaWei · Jun 22nd, 2006, 2:45 PM

I think you're letting things buffalo you that shouldn't. Probably because of that 'friend' of yours. Suppose you express one or two things that seem incomprehensible to you and let us take a shot at them. There is this about learning: something turns on the lightbulb above someone's head, but it takes a completely different slant to do the same thing for another.

peaceofpi · Jun 22nd, 2006, 2:56 PM

This problem existed before the whole Assembly debate, I've had problems getting very far in programming languages since I started.

So far, I've got most of the "basics" down. I can do if, else (if), while, all that stuff. This "for" thing has me a little intimidated, but I might've just not read enough into it.

Like I said, arrays have me confused as well. I can declare an array fine, and do some small things with the data inside; I guess I just don't know why I should use it. I also don't get why char variableName[]; would be more effective than string variableName;, but I'm still new.

I'm also working on figuring out functions and stuff, since I think it would probably make for cleaner code in large scripts. (One thing I'd like to learn, if possible, is defining functions in one file and being able to use them in your main one)

Again, a lot of the tutorials confuse me. As if they're not complicated enough, none of them go in the exact same order. So I might have a small grasp on one subject, until it gets too complicated, then move on to "chapter 3" in another tutorial where they teach something else. This causes me to do less studying than I should, since I want to learn.

Jessehk · Jun 22nd, 2006, 3:11 PM

Quote:

Originally Posted by peaceofpi

I also don't get why char variableName[]; would be more effective than string variableName;, but I'm still new.

It wouldn't, but that is only because arrays of chars were replaced by std::strings.

Arrays are useful when you want to keep track of a bunch of similar values. In many cases, std::vector in C++ can replace them, though there are still some valid uses. Here is an example:

(Toggle Plain Text)

#include <iostream>

int main() {
    // Declare an array to hold 5 scores, all of type int.
    int scores[5];

    // I'm writing this in a format that is easier to comment
    // usually 'for' loops would be written all in one line.
    //
    for(int x = 0;  //Set 'x' to be 0. It is only set once.
        x < 5;      //Iterate while x is less then 5.
        x++)        //At every iteration, increase the value of 'x' by 1
    {
        std::cout <<  "Enter score: ";

        //Get input for each successive element in the array
        std::cin >> scores[x];
    }

    std::cout << "You entered the following scores:\n";

    //Display the contents of the array.
    for(int x = 0; x < 5; x++)
        std::cout << scores[x] << std::endl;
}

coldDeath · Jun 22nd, 2006, 3:15 PM

I'll just explain a for loop for you.

In a lot of langauges you can find for loops. As you say you understand while loops I can easily explain how to use them.

Here is an example of a for loop:

(Toggle Plain Text)

for(int x = 1; x < 11; x++;){
   std::cout<< x <<std::endl;
}

This code would write the numbers 1 to 10.

Firstly you make your new variable:

(Toggle Plain Text)

for(int x = 1; x < 11; x++){
   std::cout<< x <<std::endl;
}

This variable is named x in this loop and it will last until the for loop ends, then it will be discarded.

Next, you make a condition, here we have "x < 11" this basically means: While x is less than 11, continue the loop.

Then you state what will happen to the variable after each loop, in this case I use x++ which increments the value by one.

So this for loop would look like this if it was a while loop:

(Toggle Plain Text)

int x = 1;
while (x < 11){ 
   std::cout<< x <<std::endl; 
   x++; /* increment x by one */
}

For loops can differ a lot from that small example but this is the general idea. You can do a lot of other things like leaving parameters out.

:banana:

peaceofpi · Jun 22nd, 2006, 3:26 PM

Aha. So a "for" is (basically) initializing a variable combined with a while loop of some sort.

I'm creating my own examples (by memory, without looking at what you gave me) to see if I can get it right on my own. Hitting some speed bumps, but the whole for thing is clear now.

I guess the next thing I need to tackle is pointers, which really threw me off.

Jimbo · Jun 22nd, 2006, 3:55 PM

A for loops works like this (one line pseudo-code definition):

(Toggle Plain Text)

for(Initialization; Condition; Update)
{
  // ...
}

The first part you initialize a variable for using in the loop. This is usually an array index, iterator, or something similar (not always the case though). Then you have a conditional statement, determining whether to continue the loop. Then you have an update segment to update anything for the next iteration. A for loop can also be written as:

(Toggle Plain Text)

Initialization;
while(Condition)
{
  // ...
  Update;
}

Remember though, that any variables decared in the Initialization of a for loop will only exist in the scope of that loop.

LOI Kratong · Jun 22nd, 2006, 4:04 PM

peaceofpi, I wouldn't even try and touch pointers until you at least have a fairly good grasp of the rest of the basic stuff you've mentioned, they throw a lot of people off at first, try to tackle them with a clear head, without wondering why the heck the example is doing that thing with that arrayjamawhatjimacallit!

But in all seriousness I think people will agree with me on that, get a good foundation, then expand!

Prm753 · Jun 22nd, 2006, 4:06 PM

But when you do look at pointers, head over to http://daweidesigns.com and read up about pointers there.

Namingishard · Jun 22nd, 2006, 4:41 PM

When your stuck on something, dont just skip it and keep going, and going, stop, backup and read it again, almost always works for me.
Its easy to say...oh that doesn't look to importent and skip it "For now",
but thats what gets you in trouble >_<, i did alot of that when i first started,
Then i got smart and just read everything multiple times.
Anyways good luck =P

Jun 22nd, 2006, 2:25 PM	#1
peaceofpi hi: for(;;) goto hi; Join Date: Jun 2006 Posts: 123 Rep Power: 3	Are there any lessons for idiots? I mean, I'm not an idiot. But, I just can't keep up with a lot of lessons online. The one at cplusplus.com? Lost me. Anything on Google? Lost me. I downloaded "Wrox - C++ tutorial.chm" and it's been pretty good to me, but now I'm lost again at arrays. Eventually all lessons seem to assume you know a lot. Is there anything besides a real life book (next plan) anyone can recommend to me, that teaches C++, while..."talking slow"? __________________ How do you play Religious Roulette? Stand around in a circle and blaspheme till someone gets struck by lightning.

Jun 22nd, 2006, 2:45 PM	#2
DaWei Resident Grouch Join Date: Jun 2005 Posts: 6,453 Rep Power: 10	I think you're letting things buffalo you that shouldn't. Probably because of that 'friend' of yours. Suppose you express one or two things that seem incomprehensible to you and let us take a shot at them. There is this about learning: something turns on the lightbulb above someone's head, but it takes a completely different slant to do the same thing for another. __________________ Abstraction doesn't make it impossible to write bad code; it makes it possible to write superior code. Contributor's Corner: Grumpy on C++ Exceptions DaWei on Pointers

Jun 22nd, 2006, 2:56 PM	#3
peaceofpi hi: for(;;) goto hi; Join Date: Jun 2006 Posts: 123 Rep Power: 3	This problem existed before the whole Assembly debate, I've had problems getting very far in programming languages since I started. So far, I've got most of the "basics" down. I can do if, else (if), while, all that stuff. This "for" thing has me a little intimidated, but I might've just not read enough into it. Like I said, arrays have me confused as well. I can declare an array fine, and do some small things with the data inside; I guess I just don't know why I should use it. I also don't get why char variableName[]; would be more effective than string variableName;, but I'm still new. I'm also working on figuring out functions and stuff, since I think it would probably make for cleaner code in large scripts. (One thing I'd like to learn, if possible, is defining functions in one file and being able to use them in your main one) Again, a lot of the tutorials confuse me. As if they're not complicated enough, none of them go in the exact same order. So I might have a small grasp on one subject, until it gets too complicated, then move on to "chapter 3" in another tutorial where they teach something else. This causes me to do less studying than I should, since I want to learn. __________________ How do you play Religious Roulette? Stand around in a circle and blaspheme till someone gets struck by lightning.

Jun 22nd, 2006, 3:15 PM	#5
coldDeath Expert Programmer Join Date: Aug 2005 Location: UK Posts: 862 Rep Power: 4	I'll just explain a for loop for you. In a lot of langauges you can find for loops. As you say you understand while loops I can easily explain how to use them. Here is an example of a for loop: (Toggle Plain Text) for(int x = 1; x < 11; x++;){ std::cout<< x <<std::endl; } for(int x = 1; x < 11; x++;){ std::cout<< x <<std::endl; } This code would write the numbers 1 to 10. Firstly you make your new variable: (Toggle Plain Text) for(int x = 1; x < 11; x++){ std::cout<< x <<std::endl; } for(int x = 1; x < 11; x++){ std::cout<< x <<std::endl; } This variable is named x in this loop and it will last until the for loop ends, then it will be discarded. Next, you make a condition, here we have "x < 11" this basically means: While x is less than 11, continue the loop. Then you state what will happen to the variable after each loop, in this case I use x++ which increments the value by one. So this for loop would look like this if it was a while loop: (Toggle Plain Text) int x = 1; while (x < 11){ std::cout<< x <<std::endl; x++; /* increment x by one / } int x = 1; while (x < 11){ std::cout<< x <<std::endl; x++; / increment x by one / } For loops can differ a lot from that small example but this is the general idea. You can do a lot of other things like leaving parameters out. :banana: __________________ Programming Tutorials - Linux Installation Guide - Learn Python - Learn C++ Got Slack? Join us at #programmingforums* @ irc.freenode.net! My software never has bugs. It just develops random features.

Jun 22nd, 2006, 3:26 PM	#6
peaceofpi hi: for(;;) goto hi; Join Date: Jun 2006 Posts: 123 Rep Power: 3	Aha. So a "for" is (basically) initializing a variable combined with a while loop of some sort. I'm creating my own examples (by memory, without looking at what you gave me) to see if I can get it right on my own. Hitting some speed bumps, but the whole for thing is clear now. I guess the next thing I need to tackle is pointers, which really threw me off. __________________ How do you play Religious Roulette? Stand around in a circle and blaspheme till someone gets struck by lightning.

Jun 22nd, 2006, 3:55 PM	#7
Jimbo Battle Programmer Join Date: Feb 2006 Location: Bellevue, WA, USA Posts: 773 Rep Power: 3	A for loops works like this (one line pseudo-code definition): (Toggle Plain Text) for(Initialization; Condition; Update) { // ... } for(Initialization; Condition; Update) { // ... } The first part you initialize a variable for using in the loop. This is usually an array index, iterator, or something similar (not always the case though). Then you have a conditional statement, determining whether to continue the loop. Then you have an update segment to update anything for the next iteration. A for loop can also be written as: (Toggle Plain Text) Initialization; while(Condition) { // ... Update; } Initialization; while(Condition) { // ... Update; } Remember though, that any variables decared in the Initialization of a for loop will only exist in the scope of that loop.

Jun 22nd, 2006, 4:04 PM	#8
LOI Kratong Professional Programmer Join Date: May 2005 Location: Woo - Boot Sector! Posts: 294 Rep Power: 4	peaceofpi, I wouldn't even try and touch pointers until you at least have a fairly good grasp of the rest of the basic stuff you've mentioned, they throw a lot of people off at first, try to tackle them with a clear head, without wondering why the heck the example is doing that thing with that arrayjamawhatjimacallit! But in all seriousness I think people will agree with me on that, get a good foundation, then expand! __________________ www.heldtogether.co.uk

Jun 22nd, 2006, 4:06 PM	#9
Prm753 Professional Programmer Join Date: Oct 2005 Location: United States Posts: 447 Rep Power: 4	But when you do look at pointers, head over to http://daweidesigns.com and read up about pointers there. __________________ The world's first athletic computer geek! The home of PrProgramsStudios How not to post a question: <-- Please don't reply

Jun 22nd, 2006, 4:41 PM	#10
Namingishard Newbie Join Date: Feb 2006 Location: TX Posts: 23 Rep Power: 0	When your stuck on something, dont just skip it and keep going, and going, stop, backup and read it again, almost always works for me. Its easy to say...oh that doesn't look to importent and skip it "For now", but thats what gets you in trouble >_<, i did alot of that when i first started, Then i got smart and just read everything multiple times. Anyways good luck =P

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Programming Forums > Application Development > C++

Are there any lessons for idiots?