Functions and Recursive Functions - A Concise and Practical Introduction to Programming Algorithms in Java - page 66

return result ;
}

static double F( double x)
double result ;
r e s u l t =1.0+G( x ∗ x) ;
return result ;
}

public static void main ( String [ ] args )

double y;
y=F(5.0) ;
System . out . println ( "y=" +y ) ;
}

}

For example, considering the above program, the function call stack evolves as
follows:

Step 1 2 3 4 5 6 7

call
main

call
F

call
G

finish
G

finish
F

finish
main

Action: run

G
F
main

Function
stack

F
main

F
main

∅ ∅

main main

Note that since arguments are passed by values, the local variables of the calling
functions are not changed. To emphasize this point, consider the following toy
sample program:

Program 3.7 Pass-by-value does not change local variable of calling functions
class PassByValue

{
static void F( double x)
x=3; // Here is the catch. Take care of pass-by-value.
System . out . println ( "Before exiting F, value of x:" +x ) ;
} public static void main ( String [ ]

args )

double x=5;
F(x) ;
System . out . println ( "value of x:" +x ) ;
}

}

We get from the pass-by-value mechanism the following output:

Before exiting F, value of x:3.0
value of x:5.0