Operator + with strings
You have used the operator + with numbers. When you use + with numbers, the result is also a number. However, if you use operator + with strings, it concatenates them e.g.5 + 6 results in to 11.
“5” + “6” results in to “56”.
“17” + “A, V. Vihar” result in to “17 A, V. Vihar”
“abc” + “123” results in to “abc 123”
“” + 5 + “xyz” results in to “5xyz”
“” + 5 results in to “5”
(In above two expressions Java would internally convert 5 in to “5” first and then concatenate with “xyz” and “” respectively.)
Increment/Decrement Operators (++, --)
Java includes two useful operators not generally found in other computer languages (expect C and C++). These are the increment and decrement operators, ++ and --. The operators ++ adds 1 to its operand, and – subtracts one.In other words,
a = a + 1;
is the same as
++a ; or a++;
And
a = a – 1
is the same as
--a ; or a --;
However, both the increment and decrements come in to two varieties: they may either precede of=r fallow the operand. The prefix version comes before the operand (as in ++ a or -- a) and the post-fix version comes after the operand (as in a++ or a--). The two version have the same effect upon the operand, but they differ when they take place in an expression.