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C Basics
course content

Course Content

C Basics

C Basics

1. Introduction
Structure of the C-ProgramEssentials of C ProgramHow to Run the Program?
2. Data
DataVariablesPrintfIntroduction to ArraysTwo Dimensional ArraysChar and StringSizeofPrintf PracticeSizeof Practice
3. Operators
Assignment, Comparison, Not Equal ToSum, Difference, Increment, DecrementMultiplication, Division and ModuloComparison OperatorsComparison Operators PracticeLogical OperatorsLogical Operators Practice
4. Control Statements
If-else Operatorif-else Operator PracticeTernary OperatorSwitch, BreakWhile, Do-WhileFor, ContinueFor Loop Practice
5. Functions
Structure of the FunctionDeclaration, Type and ReturnArgumentsPassing ArgumentsHeader, Prototypes Void, Recursion
6. Pointers
Pointers are around UsReferences and DereferencesPointersMalloc and FreeFunctions, Arrays and Two PointersVoid

bookPointers

Using the reference operator & and the dereference operator *, we can create and work with pointers.

A pointer is a data type, just like int, char, or double. The pointer is designed to store an address, which you can obtain using the & operator. To declare a pointer, prepend it with the * character.

In essence, a pointer is a variable that holds the address of another object.

Note

Typically, pointers are named by prefixing the letter p to the name of the object they're pointing to.

When you dereference a pointer, you access the value of the variable it points to.

c

Main

copy

              
1234567891011121314

            
#include <stdio.h>

int main()
{
    int x = 22543; // variable
    
    int* pX = &x; // `pX` is pointer to `x`

    printf("The value of `pX` is %p\n", pX); // value of pointer `pX`
    
    printf("The value of `x` by pointer `pX` is %d\n", *pX); // pointer dereference
    
    return 0;
}

Note

*(&variable) == *pVariable

If you attempt to dereference a null pointer, the compiler will raise an error:

Example provided to showcase the mistake

c

Main

copy

              
12345678910

            
#include <stdio.h>

int main()
{
    int* pX;

    printf("x = %p", pX);

    return 0;
}

Task

Determine the size of int and double pointers.

Switch to desktopSwitch to desktop for real-world practiceContinue from where you are using one of the options below
Everything was clear?

How can we improve it?

Thanks for your feedback!

Section 6. Chapter 3
toggle bottom row

bookPointers

Using the reference operator & and the dereference operator *, we can create and work with pointers.

A pointer is a data type, just like int, char, or double. The pointer is designed to store an address, which you can obtain using the & operator. To declare a pointer, prepend it with the * character.

In essence, a pointer is a variable that holds the address of another object.

Note

Typically, pointers are named by prefixing the letter p to the name of the object they're pointing to.

When you dereference a pointer, you access the value of the variable it points to.

c

Main

copy

              
1234567891011121314

            
#include <stdio.h>

int main()
{
    int x = 22543; // variable
    
    int* pX = &x; // `pX` is pointer to `x`

    printf("The value of `pX` is %p\n", pX); // value of pointer `pX`
    
    printf("The value of `x` by pointer `pX` is %d\n", *pX); // pointer dereference
    
    return 0;
}

Note

*(&variable) == *pVariable

If you attempt to dereference a null pointer, the compiler will raise an error:

Example provided to showcase the mistake

c

Main

copy

              
12345678910

            
#include <stdio.h>

int main()
{
    int* pX;

    printf("x = %p", pX);

    return 0;
}

Task

Determine the size of int and double pointers.

Switch to desktopSwitch to desktop for real-world practiceContinue from where you are using one of the options below
Everything was clear?

How can we improve it?

Thanks for your feedback!

Section 6. Chapter 3
toggle bottom row

bookPointers

Using the reference operator & and the dereference operator *, we can create and work with pointers.

A pointer is a data type, just like int, char, or double. The pointer is designed to store an address, which you can obtain using the & operator. To declare a pointer, prepend it with the * character.

In essence, a pointer is a variable that holds the address of another object.

Note

Typically, pointers are named by prefixing the letter p to the name of the object they're pointing to.

When you dereference a pointer, you access the value of the variable it points to.

c

Main

copy

              
1234567891011121314

            
#include <stdio.h>

int main()
{
    int x = 22543; // variable
    
    int* pX = &x; // `pX` is pointer to `x`

    printf("The value of `pX` is %p\n", pX); // value of pointer `pX`
    
    printf("The value of `x` by pointer `pX` is %d\n", *pX); // pointer dereference
    
    return 0;
}

Note

*(&variable) == *pVariable

If you attempt to dereference a null pointer, the compiler will raise an error:

Example provided to showcase the mistake

c

Main

copy

              
12345678910

            
#include <stdio.h>

int main()
{
    int* pX;

    printf("x = %p", pX);

    return 0;
}

Task

Determine the size of int and double pointers.

Switch to desktopSwitch to desktop for real-world practiceContinue from where you are using one of the options below
Everything was clear?

How can we improve it?

Thanks for your feedback!

Using the reference operator & and the dereference operator *, we can create and work with pointers.

A pointer is a data type, just like int, char, or double. The pointer is designed to store an address, which you can obtain using the & operator. To declare a pointer, prepend it with the * character.

In essence, a pointer is a variable that holds the address of another object.

Note

Typically, pointers are named by prefixing the letter p to the name of the object they're pointing to.

When you dereference a pointer, you access the value of the variable it points to.

c

Main

copy

              
1234567891011121314

            
#include <stdio.h>

int main()
{
    int x = 22543; // variable
    
    int* pX = &x; // `pX` is pointer to `x`

    printf("The value of `pX` is %p\n", pX); // value of pointer `pX`
    
    printf("The value of `x` by pointer `pX` is %d\n", *pX); // pointer dereference
    
    return 0;
}

Note

*(&variable) == *pVariable

If you attempt to dereference a null pointer, the compiler will raise an error:

Example provided to showcase the mistake

c

Main

copy

              
12345678910

            
#include <stdio.h>

int main()
{
    int* pX;

    printf("x = %p", pX);

    return 0;
}

Task

Determine the size of int and double pointers.

Switch to desktopSwitch to desktop for real-world practiceContinue from where you are using one of the options below
Section 6. Chapter 3
Switch to desktopSwitch to desktop for real-world practiceContinue from where you are using one of the options below
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