A value of type char can be assigned to a variable of type int. An widening conversion will convert the value to an int.

An assignment statement is an expression statement. The value of the expression statement is the value of the expression on the right-hand side. Since the assignment operator is right associative, the statement a = b = c = 20 is evaluated as follows: (a = (b = (c = 20))). This results in the value 20 being assigned to c, then the same value being assigned to b and finally to a. The program will compile, and print 20, when run.

Strings are objects. The variables a, b, and c are references that can denote such objects. Assigning to a reference only changes the reference value. It does not create a copy of the source object or change the object denoted by the old reference value in the target reference. In other words, assignment to references only affects which object the target reference denotes. The reference value of the "cat" object is first assigned to a, then to b, and later to c. The program prints the string denoted by c, i.e., "cat".

A binary expression with any floating-point operand will be evaluated using floating-point arithmetic. Expressions such as 2/3, where both operands are integers, will use integer arithmetic and evaluate to an integer value. In (e), the result of (0x10 * 1L) is promoted to a floating-point value.

The / operator has higher precedence than the + operator. This means that the expression is evaluated as ((1/2) + (3/2) + 0.1). The associativity of the binary operators is from left to right, giving (((1/2) + (3/2)) + 0.1). Integer division results in ((0 + 1) + 0.1) which evaluates to 1.1.

0x10 is a hexadecimal literal equivalent to the decimal value 16. 10 is a decimal literal. 010 is an octal literal equivalent to the decimal value 8. The println() method will print the sum of these values, which is 34, in decimal form.

The unary + and - operators with right-to-left associativity are used in the valid expressions (b), (c), and (f). Expression (a) tries to use a nonexistent unary - operator with left-to-right associativity, expression (d) tries to use a decrement operator (--) on an expression that does not resolve to a variable, and expression (e) tries to use a nonexistent unary * operator.

The expression evaluates to –6. The whole expression is evaluated as (((-(-1)) - ((3 * 10) / 5)) - 1) according to the precedence and associativity rules.

In (a), the conditions for implicit narrowing conversion are fulfilled: the source is a constant expression of type int, the destination type is of type short, the value of the source (12) is in the range of the destination type. The assignments in (b), (d), and (e) are valid, since the source type is narrower than the target type and an implicit widening conversion will be applied. The expression (c) is not valid. Values of type boolean cannot be converted to other types.