How should you Swap 2 numbers in a single line?

Answer 1

Swapping two values in a single statement is made possible through a series of three XOR/assign operations, alternating the operands.

Consider the following declarations:

int x = 0;

int y = 1;

The following statement will swap the values of x and y:

x ^= y ^= x ^= y; // swap

The same statement implemented as a function:

void swap(int &x, int &y){ x ^= y ^= x ^= y; }

Answer 2

Depending on your compiler, you may be able to use:

a = a+ b - (b = a);

This seems to work with gcc.

Using Microsoft's cl.exe (c++) gives the following output:

before swap: a = 5, b = 21

after swap: a = 5, b = 5

If this line does not work, another option would be to use your one line to make a function call, something like: void swap(int &x, int &y) { int temp = x; x = y; y = temp; }

int main() { int a = 10, b = 34; cout << "before swap: a = " << a << ", b = " << b << endl;

swap(a, b);

cout << "after swap: a = " << a << ", b = " << b << endl; return 0; }

Answer 3

a=a+b-(b=a); // Swaps variables a and b

Answer 4

temp=a; a=b; b=temp;