if (variable == value)
      * - If no value given
 
  
if (variable! = value)
      * - If it has a value greater or equal at least:
 
  
if (variable> = value)
      * - If it has a value less or equal at least:
 
  
if (variable <= value)
 

This instruction may have a second part, which is optional.
 
  
if (condition)
(
)
else
(
)
 Between the () "else" is executed only if the condition is false / not take place.
 

Examples
 
  
# include 

void main ()
(
       int a;
       cost << "Give value:";
       CIN>> a;
       if (a> = 0)
             cost << "You entered a positive number";
       else
             cost << "You entered a negative number";
)
 There is another possibility:
 
  
# include 

void main ()
(
       int a;
       cost << "Give value:";
       CIN>> a;
       if (a> 0)
             cost << "You entered a positive number";
       else if (a <0)
             cost << "You entered a negative number";
       else
             cost << "You entered the void;
)
 And the "else if" continued ....
 
  
# include 
void main ()
(
       int a, b;
       cost << "a =";
       CIN>> a;
       cost << "b =";
       CIN>> b;

       if (a> b)
             cost < 

  
# include 
void main ()
(
       int a;
       cost << "Enter a different value of 5;
       CIN>> a;
       if (a! = 5)
             cost << "Correctly";
       else
             cost << "false";
)
 Everything is different from 0 is considered true if the condition, and that 0 is false.
 

Extra

* Operator & & - "si"

- General form
 
  
if (conditie1 & conditie2)
 - The condition is considered true only if both conditions are true

- Example:

1.
 
  
int a = 5, b = 3;
if (a == 5 & & b == 3)
 
  
cost << "truth";
 2.
 
  
int a = 5, b = 4;
if (a == 5 & & b == 3)
             cost << "false";
 So with this operator we can find out if a variable is located in a desirable:
 
  
# include 

void main ()
(
             int a;
             cost << "a =";
             CIN>> a;
             if (a> = 1 & & a <= 10)
                         cost < 
Or read from the keyboard:
 
  
# include 

void main ()
(
             int a, x, y;
             cost << "top range";
             CIN>> x;
             cost << "End of interval:";
             CIN>> y;
             cost << "a =";
             CIN>> a;
             if (a> = x & & a <= y)
                         cost < 
* The operator | | - or

- General form
 
  
 if (conditie1 | | conditie2)
 - The condition is considered true if at least one of the conditions is true

- Examples:
  
int a = 5;
if (a == 5 | | a == 3)
 
  
cost << "truth";
 
 
  
int a = 5;
if (a == 4 | | a == 3)
 
  
cost << "false";
 Examples:
 
  
# include 

void main ()
(
             int a;
             cost << "a =";
             CIN>> a;
             if (a> 0 | | a <0)
                         cost < 
 
# include 

void main ()
(
             int a;
             cost << "a =";
             CIN>> a;
             if (a == 3 | | a <0)
                         cost < 
So much about IF.