Arrays( I have the code but can you confirm it 100000%)

[tiptip]

Hello guys, the question is:
Generate code to declare an integer array,Int_Var, of size 100 and write a C++ Program to carry out the following steps:

a) Assign each array element an initial value of 0;
b) Using a loop to give the first five array elements the following values: Int_Var[0]=0;
Int_Var[1]=1; Int_Var[2]=2; Int_Var[3]=3; Int_Var[4]=4.

c) Using a loop to determine the values for each integer to be beginning from the array element Int_Var[4]:
Array element Int_Var[4];
Int_Var[i]=Int_Var[i-1] + Int_Var[i-2];


And this the code, Can you please confirm it:

#include<iostream>

int int_Var[100]; //global variable

void main(void) {

for(int i = 0; i <= 100;i++){ // Array initialization

int_Var[i] = 0;

}

for (int ii = 0; ii<= 4;ii++){ //assigning the value 0-4 in the array
int_Var[ii] = ii;
}
for(int y = 4; y<= 100; y++){ // Output the value of the array
int value ;
value = int_Var[y];

cout<<"The Value of the Array beginning from array index 4 is :"<<" "<<value<<"\n";
}
}

Can you please correct it for me as it is not being compiled. There is an error that I don't know where. And can you please tell me if this code answers the question perfectly.

The error I get is:
error C2065: 'cout' : undeclared identifier


Thanks in advance

[bluezor]

You aren't using namespace std so you will need to add std::cout as a prefix.

Also what's with the random global variable? Seems useless and works if you put it in main(). Main should also be int main(), as void main() isn't standard.

[tiptip]

so this is the new code:

#include<iostream>
using namespace std;
int int_Var[100]; //global variable

int main() {

for(int i = 0; i <= 100;i++){ // Array initialization

int_Var[i] = 0;

}

for (int ii = 0; ii<= 4;ii++){ //assigning the value 0-4 in the array
int_Var[ii] = ii;
}
for(int y = 4; y<= 100; y++){ // Output the value of the array
int value ;
value = int_Var[y];

cout<<"The Value of the Array beginning from array index 4 is :"<<" "<<value<<"\n";
return 0;
}
}

The output I am getting is the following:

The Value of the Array beginning from array index 4 is : 4



Is this output correct according to the question asked?

can you check this for me pls.

Thanks in responce.

[tiptip]

Can anyone answer me

[Bazzy]

You didn't do this:

c) Using a loop to determine the values for each integer to be beginning from the array element Int_Var[4]:
Array element Int_Var[4];
Int_Var[i]=Int_Var[i-1] + Int_Var[i-2];

What should this do?

for(int y = 4; y<= 100; y++){ // Output the value of the array
int value ;
value = int_Var[y];

cout<<"The Value of the Array beginning from array index 4 is :"<<" "<<value<<"\n";
return 0;
}

[demosthenes2k8]

Move the return 0 outside of the third for loop.
And you forgot another loop for setting the variables according to Int[i-1]+Int[i-2]

[tiptip]

So this is the code till now,

can somebody help me in part c, I don't really get it.

Thanks

#include<iostream>
using namespace std;
int int_Var[100]; //global variable

int main() {

for(int i = 0; i <= 100;i++){ // Array initialization

int_Var[i] = 0;

}

for (int ii = 0; ii<= 4;ii++){ //assigning the value 0-4 in the array
int_Var[ii] = ii;
}
for(int y = 4; y<= 100; y++){ // Output the value of the array
int value ;
value = int_Var[y];

cout<<"The Value of the Array beginning from array index 4 is :"<<" "<<value<<"\n";
}
return 0;
}

can somebody help me in part c, I don't really get it.
Thanks

[Bazzy]

Part C: make a loop starting from 4 to the array end and inside it you should have this line: Int_Var[i]=Int_Var[i-1] + Int_Var[i-2];

[tiptip]

I added the following code lines:

#include<iostream>
using namespace std;
int int_Var[100]; //global variable

int main() {

for(int i = 0; i <= 100;i++){ // Array initialization

int_Var[i] = 0;

}

for (int ii = 0; ii<= 4;ii++){ //assigning the value 0-4 in the array
int_Var[ii] = ii;
}
for(int y = 4; y<= 100; y++){ // Output the value of the array
int value ;
value = int_Var[y];
int_Var[i]=int_Var[i-1] + int_Var[i-2];
cout<<"The Value of the Array beginning from array index 4 is :"<<" "<<value<<"\n";
}
return 0;
}

I am getting syntax error, could someone modify the code and give me it in order for it to work perfectly please.

[tiptip]

Ok guys, I got the following, Is this true:

#include<iostream>
using namespace std;
int int_Var[100];

int main() {

for(int i = 0; i <= 100;i++){ 

int_Var[i] = 0;

}
for (int ii = 0; ii<= 4;ii++){ 
int_Var[ii] = ii;
}
for(int y = 4; y<= 100; y++){ 

int_Var[y]=int_Var[y-1]+int_Var[y-2];
int value ;
value = int_Var[y];

cout<<"The Value the Array beginning from array index 4 is :"<<" "<<value<<"\n";
}
return 0;
}

[Bazzy]

You don't need lines 19 and 20, you can just show int_Var[y]

[tiptip]

So it is finally like this:

#include<iostream>
using namespace std;
int int_Var[100];
int main() {
for(int i = 0; i < 100;i++){ 
int_Var[i] = 0;
}
for (int ii = 0; ii< 4;ii++){ 
int_Var[ii] = ii;
}
for(int y = 4; y< 100; y++){ 
cout<<"The Value the Array beginning from array index 4 is :"<<" "<<value<<"\n";
}
return 0;
}

I am getting in the output some negative values. Is is correct. Can array values be negative?

[Bazzy]

You removed line 17 of your previous code, that was an important one

[tiptip]

Oh, yes, now it is working, can I ask you, if you debug the code below, you will get some negative values. For example, I get the following output:

The Value the Array 46 beginning from array index 4 is - then a number.


How come I get a negative number, altough, if you use the equation, we can't get a -ve number???

#include<iostream>
using namespace std;
int int_Var[100];
int main() {
for(int i = 0; i < 100;i++){ 
int_Var[i] = 0;
}
for (int ii = 0; ii< 4;ii++){ 
int_Var[ii] = ii;
}
int z;
int value ;
for(int y = 4; y< 100; y++){ 
int_Var[y]=int_Var[y-1]+int_Var[y-2];
value = int_Var[y];
z=y;
cout<<"The Value the Array "<<z<< "\t"; cout<< "beginning from array index 4 is :"<<" "<<value<<"\n";
}
return 0;
}

[Bazzy]

The negative values are caused by too high values, try to change int_Var to an unsigned long array

[tiptip]

Exactly. I did it as the following and I got the great answers. BUT, I still think that there is something wrong, I thing I the output numbers are really very very big when comparing them to the equation. Do you have an explanation to this.
For example, for y = 10, using the equation, I should get
int_Var[10]= int_Var[10-1]+int_Var[10-2] = 9+8 = 17.

Is this correct or am I misunderstanding the calculations.

#include<iostream>
using namespace std;
unsigned long  int_Var[100];
int main() {
for(int i = 0; i < 100;i++){ 
int_Var[i] = 0;
}
for (int ii = 0; ii< 4;ii++){ 
int_Var[ii] = ii;
}
int z;
unsigned long  value ;
for(int y = 4; y< 100; y++){ 
int_Var[y]=int_Var[y-1]+int_Var[y-2];
value = int_Var[y];
z=y;
cout<<"The Value the Array "<<z<< "\t"; cout<< "beginning from array index 4 is :"<<" "<<int_Var[y]<<"\n";
}
return 0;
}

Thank you a lot. You were of massive help.

Thanks again.

[Bazzy]

int_Var[10-1] is the value of int_Var[9], not 9
so:
for int_Var[4], the value is 3+2 = 5
for int_Var[5], the value is 5+3 = 8
etc

[tiptip]

NOW I got it 100%

Thanks Bazzy, you were really of great help ans sorry for the many questions
Thanks.

TipTip