Modify variable with operations

One of the most important functionality of programming is to do calculations. And that is why computers are called computers. In order to do calculations, we need operators.


Here is the sample code:


Integer i = 10;

i *= 2; //Means i = i * 2, i is 20 now

i++; //Means i = i + 1, i is 21 now

Boolean b = i > 15; // b is true

Boolean b2 = i <= 20; //b2 is false

Boolean b3 = b && b2; // && means And, b3 is false

Boolean b4 = b || b2; // || means Or, b4 is true

String str = 'Hello ' + 'World'; //str is Hello World





Sometimes people from non-technical background may find it hard to understand statements like i = i + 1. Please note, this is not a mathematical equation. It is a statement in programming. This statement simply means get the value of i, add it by 1, then store the new value back to i.

i *= 2 is the abbreviation for i = i * 2. Similarly we can write i += 20 and i /= 2.

i++ is the abbreviation for i = i + 1; Similarly we can write i–, ++i and –1. But there is no i** or i // .

&& and || are logical operators, means And and Or.

+ in String operations means joining two strings together. Please note only + works for string. There is no -, * or / for String operation.