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How do you write a program in Perl to swap two variables without using the third one?
Use list assignment i.e. for two variables $a, $b: ($a,$b) = ($b,$a)
How do you write a c program to swap the values of two variables in unix?
#include<stdio.h> void main() { int a=2,b=4; printf("Program for swapping two numbers "); printf("Numbers before swapping"); printf("a=%d and b=%d",a,b); a=((a+b)-(b=a)); printf("Numbers after swapping"); printf("a=%d and b=%d",a,b); getch(); }
How would you write a program to swap the values of character variable using call by address?
void swap (int* a, int* b) { if (!a !b) return; // can't swap a pointer to null *a^=*b^=*a^=*b; }
Swap two number using pointer?
The only way to swap two values using call by value semantics is to pass pointer variables by value. A pointer is a variable that stores an address. Passing a pointer by value copies the address, the value of the pointer, not the pointer itself. By passing the addresses of the two values to be swapped, you are effectively passing those values by reference. Both C and C++ use pass by value semantics by default, however C++ also has a reference data type to support native pass by reference semantics. By contrast, Java uses pass by reference semantics by default. In C, to swap two variables using pass by value: void swap (int* p, int* q) { int t = *p; *p = *q; *q = t; } In C++, to swap two variables using pass by reference: void swap (int& p, int& q) { std::swap (p, q); } Note that C++ is more efficient because std::swap uses move semantics; there is no temporary variable required to move variables. With copy semantics, a temporary is required. However, with primitive data types, there is a way to swap values without using a temporary, using a chain of exclusive-or assignments: void swap (int* p, int* q) { *p^=*q^=*p^=*q; }
How do you write a program in C to swap two variables using a function?
#include<iostream> void swap(int* x, int* x){ (*x)^=(*y)^=(*x)^=(*y); } int main() { int a, b; a=10; b=20; std::cout<<"Before swap: a="<<a<<", b="<<b<<std::endl; swap(&a,&b); std::cout<<"After swap: a="<<a<<", b="<<b<<std::endl; return(0); }
