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Scoping of variables in C++
Introduction to C++ example from a Well House Consultants training course
More on Introduction to C++ [link]
Source code: rsmain.cpp Module: C231
using namespace std;
#include <iostream> /* Showing scoping of variables in C++ Variables declared within the functions / methods of a C++ program 'live' from the point at which they are declared to the end of the block in which they are declared, being kept on the stack. At that point, they are released and if the block in which they are declared is in a loop or is within a loop, they will be recreated on each subsequent entry to the block. Where a variable in an inner block is declared with the same name as a variable in an outer block, the variable in the inner block will mask the variable in the outer block while the inner block lives. */ int main () { // this k is in the outer block ... it is unmasked at the very end int k = 9; int j; cout << k << endl; // Here is a block that is used purely to scope variables! { int k = 55; cout << k << endl; } // There's a new k each time through this loop for (j=0; j<5; j++) { int k = j-15; cout << k << endl; } // And back to the original k! cout << k << endl; } /* Sample Output wizard:antrim graham$ ./rsmain 9 55 -15 -14 -13 -12 -11 9 wizard:antrim graham$ */ Learn about this subject
This module and example are covered on the following public courses:
* Learning to program in C and C++ * C++ for C Programmers * C and C++ Programming * Learning to program in C and C++ * C and C++ Programming Also available on on site courses for larger groups Books covering this topic
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