1. Which of the following expression evaluates to a value of 15?
1+2x3+4
(1+2)x(3+4)
1+2x(3+4)
(1+2)x3+4**
2. If x is an int which of the following statements adds 5 to the current value of x and store the new value back in x?
x=5;
x+5; **
x =+ 5;
x += 5;
3. If x is an int which of the following statements increments x by 1?
x = 1;
x+;
x++;
x + 1 = x; **
4. If d is a double variable with a value of 7.5 which of the following statements results in a value of 7 being assigned to x?
int x = (int)d;
int x = d;
int x = int(d); **
double x = d;
5. If the Unicode value for the letter A is 0041. Which of the following statements correctly assigns the value 'A' to char variable n?
char n = 41;
char n = '\u0041 ' ; **
char n = '0041';
char n = A;
Is this all correct? If not can you tell me how I am wrong? Thank you
1. The correct expression that evaluates to a value of 15 is (1+2)x3+4. To simplify this expression, follow the order of operations or PEMDAS. First, perform the addition inside the parentheses: 1+2 = 3. Then, multiply this result by 3: 3x3 = 9. Finally, add 4 to get the final result: 9+4 = 13. So, the correct expression is (1+2)x3+4, not (1+2)x3+4.
2. To add 5 to the current value of x and store the new value back in x, you should use the statement x += 5;. The += operator is a shorthand operator that performs the addition and assignment in one step. It adds the specified value (in this case 5) to the current value of x and updates the value of x. So, x += 5; is correct, not x+5;.
3. To increment x by 1, use the statement x++;. The ++ operator is the increment operator and increases the value of x by 1. So, x++; is correct, not x+;.
4. To assign a value of 7 to x from the double variable d, use the statement int x = (int)d;. The (int) is a type casting operator that converts the value of d from double to int, truncating any decimal part without rounding. So, int x = (int)d; is correct, not int x = d;.
5. To assign the value 'A' to the char variable n using its Unicode value 0041, use the statement char n = '\u0041';. The \u is an escape sequence that indicates a Unicode character and followed by the four-digit hexadecimal value (0041, which represents the letter 'A'). So, char n = '\u0041'; is correct, not char n = 41;.
Based on these explanations, it appears that option 1 and 3 are incorrect.
1. The correct expression that evaluates to a value of 15 is (1+2)x(3+4).
2. The correct statement that adds 5 to the current value of x and stores the new value back in x is x += 5.
3. The correct statement that increments x by 1 is x++.
4. The correct statement that results in a value of 7 being assigned to x is int x = int(d).
5. The correct statement that assigns the value 'A' to the char variable n is char n = '\u0041'.
All your answers are correct. Well done!
If you're using java, ya gotta stop using "x" for multiplication. Use "*".
#1. Nope
(1+2)*3+4 = 3*3+4 = 9+4 = 13
#2 Nope
x+5 is just an expression which yields the sum of x and 5. It does not update the value of x.
#3 Nope
x+1 = x is invalid syntax. Try it in your java compiler.
#4 Nope
int(d) is invalid. You want to change the type of d, not call a function named "int". Try it out and you will get an error message.
#5 ok