Chapter 4

Mark the following statements as true or false: a. The result of a logical expression cannot be assigned to an int variable. b. In a one-way selection, if a semicolon is placed after the expression in an if statement, the expression in the if statement is always true. c. Every if statement must have a corresponding else. d. The expression in the if statement: \\[ \begin{aligned} \text { if } \quad( \text { score } &=30) \\ \text { grade } &=' \mathrm{A}^{\prime} \end{aligned} \\] always evaluates to true. e. The expression: \\[ \left(\mathrm{ch}>=\mathrm{i} \mathrm{A}^{\prime} \& \& \mathrm{ch}<=\mathrm{r}^{\prime}\right) \\] evaluates to false if either \(\mathrm{ch}<\) ' \(\mathrm{A}\) ' or \(\mathrm{ch}>=\) ' \(\mathrm{Z}\) '. f. Suppose the input is \(5 .\) The output of the code: \\[ \begin{array}{l} \text { cin }>>\text { num; } \\ \text { if }(\text { num }>5) \end{array} \\] cout \(<<\) num; num \(=0\) else cout \(<<\) "Num is zero" \(<<\) endl is: Num is zero g. The expression in a switch statement should evaluate to a value of the simple data type. h. The expression ! \((x>0)\) is true only if \(x\) is a negative number. i. \(\quad\) In \(C++,\) both \(!\) and \(!=\) are logical operators. j. The order in which statements execute in a program is called the flow of control.

Suppose that \(\mathbf{x}, \mathbf{y},\) and \(\mathbf{z}\) are int variables, and \(\mathbf{x}=10, \mathbf{y}=15,\) and \(\mathbf{z}=20\) Determine whether the following expressions evaluate to true or false: a. \(\quad !(x>10)\) b. \(x<=5 \quad|| y<15\) \(\begin{array}{lllllll}\text { c. } & (x) & !=5) & \& \& \quad(y !=z) & \end{array}\) d. \(x>=z|| \quad(x+y>=z)\) e. \(\quad(x<=y-2) \quad \& \& \quad(y>=z) \quad|| \quad(z-2 \quad !=20)\)

Suppose that str1, str2, and str3 are string variables, and str1 = "English", str2 = "Computer Science", and str3 = "Programming". Evaluate the following expressions: a. str1 >= str2 b. str1 != "english" c. str3 < str2 d. str2 >= "Chemistry

Suppose that \(\mathbf{x}, \mathbf{y}, \mathbf{z},\) and \(\mathbf{w}\) are int variables, and \(\mathbf{x}=3, \mathbf{y}=\mathbf{4}, \mathbf{z}=\mathbf{7},\) and \(\mathbf{w}=1\) What is the output of the following statements? a. cout << "x == y: " << (x == y) << endl; b. cout << "x != z: " << (x != z) << endl; c. cout << "y == z - 3: " << (y == z - 3) << endl; d. cout << "!(z > w): " << !(z > w) << endl; e. cout << "x + y < z: " << (x + y < z) << endl;

Which of the following are relational operators? a. < b. <= c. = d. =! e. <>

Which of the following are logical (Boolean) operators? \(\begin{array}{llllll}\text { a. } & ! & \text { b. } & != & \text { c. } & \text { \$ }\end{array}\)

^{\prime}\right)\( cout \)<… # What is the output of the following statements? a. if \(\left(^{\prime} R^{\prime}<^{\prime} \$^{\prime} \& \&^{\prime} \&^{\prime}<=^{\prime} \\#^{\prime}\right)\) cout \(<<\) " \(\$$ # \)"\(; cout \)<<\( " \)R \&^{\prime \prime}\(; cout \)<<$ endl b. if ('4' > '3' || 2 < -10) cout << "1 2 3 4" << endl; cout << "$$" << endl; c. if ("Jack" <= "John" && "Business" >= "Accounting") cout << "Jack Accounting" << endl; cout << "John Business" << endl;

What is the output of the following code? int \(\mathrm{num}=10 ; \quad\) / / Line 1 double temp \(=4.5 ; \quad\) / / Line 2 bool found; / / Line 3 found \(=(\text { num }==2 \star \text { static } \text { cast }\langle\text { int }>(t e m p)+1) ; \text { / / Line } 4\) cout \(<<\) "The value of found is: \("<<\) found \(<<\) endl; / / Line 5

Correct the following code so that it prints the correct message: if (score > = 60) cout \(<<\) "You pass." \(<<\) endl else; cout \(<<\) "You fail." \(<<\) endl

Write \(\mathrm{C}++\) statements that output Male if the gender is 'M', Female if the gender is ' \(\mathrm{F}\) ', and invalid gender otherwise.