Introduction

Output:

Hello Rahul 

Here, the + operator combines two String values to create a new String.

String Concatenation

The + operator can be used to combine String values.

Output:

 Rahul Kumar

Multiple String values can be combined in a single expression.

String with Numbers

The + operator can also be used with Strings and numbers.

Output:

 Rahul is 20 years old.

When a String is involved, the + operator performs String concatenation.

Order of Evaluation

The order of an expression can change the result.

Output:

Result: 1020Result: 30

In the first expression, once Java encounters a String, the following + operations are treated as concatenation.

In the second expression, parentheses calculate 10 + 20 first.

String Comparison Expression

String expressions can also be used for comparison.

Output:

 true

The equals() method produces a boolean result based on the String content.

Using String Methods in Expressions

String methods can be part of an expression.

Output:

 JAVA Programming

Here, toUpperCase() is used as part of the String expression.

String Expression with length()

A String method can also return a value that is used in another expression.

Output:

 10

The length() method returns 5, and then 5 is added to it.

Important Example

Output:

 Name: Rahul, Age: 20, City: Delhi

This example combines multiple variables and values into one String expression.

Key Takeaways

• A String expression works with String values, variables, operators, and methods.
• The + operator is commonly used for String concatenation.
• Parentheses can be used to control the order of evaluation.
• String methods such as equals(), toUpperCase(), and length() can be used in expressions.
• String expressions can produce a String, boolean, int, or another value depending on the expression.