Swapping of two numbers without using third variable

Approach#1.
Addition and Subtraction Method

Integer a, b

read a and b

a= a+b;

b=a-b;

a=a-b;

Problem:
Incorrect result when sum of numbers will exceed the Integer range.

Approach#2. 
Multiplication and Division Method

Integer a, b

read a and b

a=a*b;

b=a/b;

a=a/b;

Problems:

1. If the value of a*b exceeds the range of integer.

2. If the value of a or b is zero then it will give wrong results.

Approach#3.
XOR Method

Integer a , b

read a and b

a=a^b;

b=a^b;

a=a^b;

Best approach to solve this problem without any pitfalls.