In Java, an expression is a combination of literals, variables, operators, and method calls that evaluates to a value. Expressions are used to compute values or produce side effects in Java programs.
Here are some examples of expressions in Java:
1 + 2 // addition expression "Hello, " + "World!" // string concatenation expression x > y // relational expression Math.sqrt(x) // method call expression
In the first example, an addition expression is used to add the values 1 and 2. In the second example, a string concatenation expression is used to concatenate the strings "Hello, " and "World!". In the third example, a relational expression is used to compare the values of x and y. In the fourth example, a method call expression is used to call the sqrt() method of the Math class and calculate the square root of x.
Expressions can be combined to create more complex expressions, and they can be used in various contexts, such as assignment statements, control statements, and method calls.