Java Tutorial Java Variables w3Schools Ch#05 Urdu Hindi

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Variables are containers for storing data values.

In Java, there are different types of variables, for example:

String - stores text, such as "Hello". String values are surrounded by double quotes

int - stores integers (whole numbers), without decimals, such as 123 or -123
float - stores floating-point numbers, with decimals, such as 19.99 or -19.99

char - stores single characters, such as 'a' or 'B'. Char values are surrounded by single quotes

boolean - stores values with two states: true or false

The general rules for constructing names for variables (unique identifiers) are:

Names can contain letters, digits, underscores, and dollar signs
Names must begin with a letter
Names should start with a lowercase letter and it cannot contain whitespace
Names can also begin with $ and _
Names are case sensitive ("myVar" and "myvar" are different variables)
Reserved words (like Java keywords, such as int or boolean) cannot be used as names

All Java variables must be identified with unique names.

These unique names are called identifiers.

Identifiers can be short names (like x and y) or more descriptive names (age, sum, totalVolume).