Introduction to C language with its basic concept

Hi guys 🙂 Varsha here and in this article we are going to discuss some basic things about C language. In this article, we will discuss loops, operators, and many other basic things in C language.

I am sure this article will definitely help you to get some brief knowledge about C language, and you can also understand the basic things about this language.

C language

C language is a programming language that is widely used for developing operating systems, games, and other applications. C is a compiled language, which means that it is converted into machine code (the language that computers can understand) by a compiler before it can be executed. A high-level language is a programming language that is closer to human language and is more abstract than a low-level language. It is easier to read, write, and understand than low-level languages, which are closer to machine code and require a deeper understanding of computer systems and hardware.

# include<stdio.h>
# include<conio.h>
void main()
{
    printf("Hello World")
}

Data types in C language: –

1. Integer
2. Float
3. Double
4. Character
5. Array
6. String
7. Pointer
8. Structured
9. Union
10. enum

Some common knowledge about C language: –

1. Token: – Token is the smallest unit of the program.
2. Character cell: – integer, floating point, character, string, special character.
3. Input – Output function: –

Scanf(“%d”, &n); used for input

Printf(“Hello”); used for output

1. Format specifier

integer: – %d

float/double: – %f

char: – %c

alphanumeric: – %x

string: – %S

Variable scope in c language

1. Local variable
2. Global variable

Local variable: – if the variable is declared and called inside the function, then it is known as a local variable.

# include<stdio.h>
# include<conio.h>
void main()
{
    int m = 10;    // local variable
    printf("%d",m);
}

Global variable: – Any variable is called a global variable if it is declared and called outside the function.

# include<stdio.h>
# include<conio.h>

int n = 20;
int main()
{
    printf("%d",n);
    return 0;
}

Default value: – All global variables and static, extern global variable has a default value.

# include<stdio.h>
# include<conio.h>

int num;
int main()
{
    

Conditional statements in c language

1. if statement
2. if-else statement
3. if-else-if ladder
4. nested if statement

if statement

Syntax:

if(condition)
{
    statement
}

Example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int n = 10;
    if(n<100)
    {
        printf("true")
    }
}

if-else statement: –

Syntax:

if(condition)
{
    statement
}
else
{
    statement
}

Example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int n = 10;
    if(n>100)
    {
        printf("true")
    }
    else
    {
        printf("false")
    }
}

if-else-if ladder: –

Syntax:

if(condition)
{
    statement
}
else if(condition)
{
    statement
}
else
{
    statement
}

Example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int n = 10, m = 20, k = 15;
    if((n>m)&&(n>k))
    {
        printf("n is largest")
    }
    else if((m>n)&&(m>k))
    {
        printf("m is largest")
    }
    else
    {
        printf("k is largest")
    }
}

Nested if statement: –

Syntax:

if(condition)
{
    if(condition)
    {
        statement;
    }
    else
    {
        statement;
    }
    else
    {
        statement;
    }
}

Example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int n = 10, m = 20;
    if(n<50)
    {
        if(m<100)
        {
            printf("true")
        }
        else
        {
            printf("flase")
        }
        else
        {
            printf("false")
        }
}

Switch Statement: –

Syntax:

switch(expression)
{
    case value1: statement;
    break;

    case value2: statement;
    break;

    default: statement;
} 

Example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int option;
    printf("Enter option number:");
    scanf("%d", &option);
    switch(option)
    {
        case1: printf("runningoption-1");
        break;
  
        case2: printf("runningoption-2");
        break;

        case3: printf("runningoption-3");
        break;

        default: printf("running default");
    }
}

Continue: –

Example:

# include<stdio.h>
# include<conio.h>

int main()
{
    int i;
    for(i=1, i<=10, i++)
    {
        if(i==5)
        continue;
        printf("%d\n",i);
    }
    return 0;
}

Loops in C language

In the C language, there are several types of loops that you can use to execute a block of code multiple times. These include:

1. For loop
2. While loop
3. do while loop
4. Nested for loop

For loop

this loop is often used when you want to execute a block of code a specific number of times.

Syntax:

for(initialization; condition; incre/decre)
{
    statement;
}

Example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int i;
    for (int i = 0; i < 10; i++) 
    {
        printf("%d\n", i);
    }
}

While loop

this loop continues to execute a block of code as long as a certain condition is met.

Syntax:

while(condition)
{
    statement;
}

Example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int i = 0;
    while (i < 10) 
    {
        printf("%d\n", i);
        i++;
    }
}

do—while loop

do—while loop is similar to a while loop, but it is guaranteed to execute the code in the loop at least once.

Syntax:

do
{
    statement;
}
while(condition);

Example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int i = 0;
    do 
    {
        printf("%d\n", i);
        i++;
    }
    while (i < 10);
}

Nested for loop

you can also use loops inside of other loops to create more complex patterns.

Syntax:

for(initialization, condition, incre/decre)
{
    for(initialization, condition, incre/decre)
    {
        statement;
    }
}

Example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int i;
    for (int i = 0; i < 10; i++) 
    {
        for (int j = 0; j < 10; j++) 
        {
            printf("%d, %d\n", i, j);
        }
    }
}

Operators in C language

In the C programming language, operators are special symbols that perform specific operations on one or more operands and produce a result. Some common operators in C include:

1. Arithmetic Operator
2. Assignment Operator
3. Comparison Operator
4. Logical Operator
5. Bitwise Operator
6. Ternary Operator
7. Relational Operator
8. Miscellaneous Operator

Arithmetic Operator

Arithmetic Operators are +, -, *, /, %, ++, –. For example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int a = 5;
    int b = 2;
    int c = a + b;   // c will be 7
    int d = a - b;   // d will be 3
    int e = a * b;   // e will be 10
    int f = a / b;   // f will be 2
    int g = a%b;  //g will be 1
}

Assignment Operator

Assignment operators are =, +=, -=, *=, /=, %=. For example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int a = 5;   // assigns the value 5 to the variable a
    a += 2;      // equivalent to a = a + 2
    a -= 2;      // equivalent to a = a - 2
    a *= 2;      // equivalent to a = a * 2
    a /= 2;      // equivalent to a = a / 2
}

Comparison Operator

comparison operators are ==, <=, >=.

# include<stdio.h>
# include<conio.h>

void main()
{
    int a = 5;
    int b = 2;
    if (a == b) 
    {
        // this code will not be executed
    }
    if (a > b) 
    {
        // this code will be executed
    }
    if (a < b) 
    {
       // this code will not be executed
    }
}

Logical Operator

Logical operators are &&, ||. For example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int a = 5;
    int b = 2;
    int c = 3;
    if (a > b && a > c) 
    {
       // this code will be executed because both conditions are true
    }
    if (a > b || a > c) 
    {
       // this code will also be executed because at least one of the conditions is true
    }
}

Bitwise Operator

Bitwise operators are &, /, XOR, <<, >>, >>>. For example:

# include<stdio.h>
# include<conio.h>

void main()
{
    int a = 5;   // 
    int b = 3;   // 
    int c = a & b;   // c will be 1 (binary representation is 001)
    int d = a | b;   // d will be 7 (binary representation is 111)
    int e = a ^ b;   // e will be 6 (binary representation is 110)
}

Ternary Operator

Ternary operators are:, ?. For example:

# include<stdio.h>
# include<conio.h>

void main()
{ 
    int a = 5;
    int b = 2;
    int c = (a > b) ? a : b;   // c will be 5 because the condition (a > b) is true
}

Relational Operator

Relational operators are <, >, <=, >=, ==, !=. For example:

# include<stdio.h>
# include<conio.h>

void main()
{ 
    int a = 5;
    int b = 2;
    if (a == b) 
    {
       // this code will not be executed because a is not equal to b
    }
    if (a > b) 
    {
       // this code will be executed because a is greater than b
    }
    if (a < b) {
       // this code will not be executed because a is not less than b
    }
}

Miscellaneous Operator

Miscellaneous operators are &, *, ?. For example:

# include<stdio.h>
# include<conio.h>

void main()
{ 
    int a = 5;
    int *p = &a;   // p is a pointer to the variable a
    *p = 7;        // this sets the value of a to 7 because *p is equivalent to a
}