C++ goto statement

A goto statement provides an unconditional jump from the goto to a labeled statement in the same function.

NOTE: Use of goto statement is highly discouraged because it makes difficult to trace the control flow of a program, making the program hard to understand and hard to modify. Any program that uses a goto can be rewritten so that it doesn't need the goto.

Syntax:

The syntax of a goto statement in 

C++ is:goto 

label; .. . label:

 statement;

Where label is an identifier that identifies a labeled statement. A labeled statement is any statement that is preceded by an identifier followed by a colon (:).

Flow Diagram:

Example:

#include <iostream> 

using namespace std; 

 int main () 

{

 // Local variable declaration:

 int a = 10;

 // do loop execution LOOP:do 

 { 

 if( a == 15) 

 { 

 // skip the iteration. a = a + 1; 

 goto LOOP; 

 }

 cout << "value of a: " << a << endl; a = a + 1;

 }

while( a < 20 );

 return 0; 

}

When the above code is compiled and executed, it produces the following result:
value of a: 10 value of a: 11 value of a: 12 value of a: 13 value of a: 14 value of a: 16 value of a: 17 value of a: 18 value of a: 19
One good use for the goto is to exit from a deeply nested routine. For example, consider the following code fragment

: for(...)

 {

 for(...)

 {

 while(...) 

{

 if(...) 

goto stop; . . . } 

 }

 }
stop: cout << "Error in program.\n";

Eliminating the goto would force a number of additional tests to be performed. A simple breakstatement would not work here, because it would only cause the program to exit from the innermost loop.