What is the output of the following Java code: `System.out.println(3 + 4 + "7");`?

In the given Java code System.out.println(3 + 4 + "7");, the operation involves both numeric addition and string concatenation.

First, the numeric values 3 and 4 are added together. In Java, when you use the + operator with two integers, it performs arithmetic addition. Therefore, 3 + 4 equals 7.

Next, the result of this addition, which is 7, is subsequently concatenated with the string "7". In Java, when you use the + operator and one of the operands is a string, it triggers string concatenation. Thus, 7 + "7" results in the string "77". This concatenation is performed as it converts the number 7 to its string equivalent and appends it to "7".

As a result, the final output of the code is "77", which is printed to the console. This is why the correct answer to the code's output is option C, which is 77.