c - Why is temporary storage needed in sorting array? -

the piece of code :

if(a[i] > a[j]){    temp = a[i];    a[i] = a[j];    a[j] = temp; } 

why temp variable has used ? when try without temp :

if(a[i] > a[j]){      a[i] = a[j]; } 

it wont work, before working when compare other variables

if don't have temp variable

temp = a[i]; a[i] = a[j]; a[j] = temp; 

then lose value in a[i] (previous assignment a[i] = a[j].

there way swap values without having using temporal value. solution here.

in c this:

int x = 10, y = 5; // code swap 'x' (1010) , 'y' (0101) x = x ^ y;  // x becomes 15 (1111) y = x ^ y;  // y becomes 10 (1010) x = x ^ y;  // x becomes 5 (0101) 

using xor operator. code here, go link find entire explanation , possible drawbacks of using solution.