We learn about JAVA user input with Scanner class, decision making with if-then-else and switch-case, then for, while, do-while loops along with advance for loop.
Marks and grades
/**
* Points Grade
* 0–29 failed
* 30–34 E
* 35–39 D
* 40–44 C
* 45–49 B
* 50–60 A
* >60 A+
*
* @author azmeer
*/
public class W05aMarksAndGrades {
public static void main(String[] args) {
System.out.println("Marks and Grades");
int mark = 61;
String grade;
if (mark > 60) {
grade = "A+";
} else if (mark >= 50) {
grade = "A";
} else if(mark >= 45){
grade = "B";
} else if(mark >= 40){
grade = "C";
} else if(mark >= 35){
grade = "D";
} else if(mark >= 30){
grade = "E";
} else {
grade = "Fail";
}
System.out.println("Your mark=" + mark + " your grade=" + grade);
}
}
Switch-Case example
/**
* Switch-case example
* Case "B" and "C" select the same response
* @author azmeer
*/
public class W05bSwitchCase {
public static void main(String[] args) {
System.out.println("Switch case test");
String grade = "C";
switch (grade) {
case "A+":
System.out.println("Well done");
break;
case "A":
System.out.println("Good job");
break;
case "B":
case "C":
System.out.println("Good attempt");
break;
default:
System.out.println("Better luck next time !");
}
}
}
Simpler if-then-else with the ternary operator
/**
* Simpler if-then-else with the ternary operator
* @author azmee
*/
public class W05cTernaryOp {
public static void main(String[] args) {
System.out.println("Odd/Even detection with the ternary operator");
int n = 5;
String q;
q = (n % 2 == 0) ? "Even" : "Odd";
System.out.println(n + " is " + q);
}
}
Loops and controls
/**
*
* @author azmeer
*/
public class W05dLoops {
public static void main(String[] args) {
System.out.println("While loop");
int max = 5;
int n = 0;
while (n < max) {
System.out.println(n + " Hello from While-Loop");
n = n + 1;
}
System.out.println("\nFor loop");
for (n = 0; n < 5; n++) {
System.out.println(n + " Hello from For-Loop");
}
System.out.println("\nDo-While loop");
n = 0;
do {
System.out.println(n + " Hello from Do-While-Loop");
n = n + 1;
} while (n < max);
/* This loop type is suitable to handle arrays and collections */
System.out.println("\nEnhaced loop");
int[] marks = {32, 54, 34, 32};
for (int oneMark : marks) {
System.out.println(oneMark + " Hello from enhanced-Loop");
}
System.out.println("\nLoop control \n");
System.out.println("\nStop at 3");
for (n = 0; n < 5; n++) {
if(n==3) {break;}
System.out.println(n + " Hello from For-Loop");
}
System.out.println("\nSkip 3");
for (n = 0; n < 5; n++) {
if(n==3) {continue;}
System.out.println(n + " Hello from For-Loop");
}
}
}