The output of the following code is:

4.0

Reason — Let's evaluate the expression step by step:

System.out.println(Math.ceil(6.4) + Math.floor(-1 - 2));

Step 1: Evaluate Math.ceil(6.4)

• The ceil method rounds a number up to the nearest integer.
• Math.ceil(6.4) → 7.0 (as ceil returns a double).

Step 2: Evaluate -1 - 2

• -1 - 2 = -3

Step 3: Evaluate Math.floor(-3)

• Math.floor(-3): The floor method rounds a number down to the nearest integer.
• Math.floor(-3) → -3.0 (as floor also returns a double).

Step 4: Add the Results

• Math.ceil(6.4) + Math.floor(-3) → 7.0 + (-3.0)
• Result = 4.0