Thread: Help me with different activities in Java program

Example 4-1

public class FourDashOne{
    public static void main(String[] args){
    int grade = 68;
if( grade > 60 ){
System.out.println("Congratulations!");
System.out.println("You passed!");
}
 
 
}

Activity 4-1
Modify Example 4-1 such that the value of int grade is through user input. (Remember BufferedReader?) Filename: ActivityFourDashOne.java

Example 4-2

public class FourDashTwo{
    public static void main(String[] args){
    int grade = 68;
if( grade > 60 ){
System.out.println("Congratulations!");
System.out.println("You passed!");
}
    else{
System.out.println("Sorry you failed");
}
 
}

Activity 4-2
Modify Example 4-2 such that the value of int grade is through user input.
Filename: ActivityFourDashOne.java

Example 4-3

public class FourDashThree{
    public static void main(String[] args){
    int grade = 68;
if( grade > 90 ){
System.out.println("Very good!");
}
else if( grade > 60 ){
System.out.println("Very good!");
}
else{
System.out.println("Sorry you failed");
}
 
}

Activity 4-3
Write an executable class that evaluates Richter magnitude scale. User inputs Richter magnitude. The program displays the description and the earthquake effects based on the table below:

Richter Magnitude Description Earthquake Effects
Less than 2.0 Micro Microearthquakes, not felt.
2.0 - 2.9 Minor Generally not felt, but recorded.
3.0 – 3.9 Minor Often felt, but rarely causes damage.
4.0 – 4.9 Light Noticeable shaking of indoor items, rattling noises.
5.0 – 5.9 Moderate Can cause major damage to poorly constructed buildings.
6.0 – 6.9 Strong Can be destructive in areas up to about 160 km across.
7.0 – 7.9 Major Can cause serious damage over large areas.
8.0 – 8.9 Great Can cause serious damage in areas several hundred miles across
9.0 – 9.9 Great Devastating in areas several thousand miles across.
10.0 + Epic Never reorded

Filename: ActivityFourDashThree.java

Example 4-4

import java.io.*;
public class FourDashFour{
    public static void main(String[] args) throws IOException{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
char choice;
 
System.out.println(“Options: “);
System.out.println(“[1] Addition “);
System.out.println(“[2] Subtraction “);
System.out.println(“[3] Multiplication “);
System.out.println(“[4] Division “);
System.out.print(“Choice: “);
choice = br.readLine().charAt(0);
 
    switch(choice) {
    case ‘1’: System.out.println(“Addition”);
                   break;            
    case ‘2’: System.out.println(“Subtraction”);
                   break;            
    case ‘3’: System.out.println(“Multiplication”);
                   break;            
    case ‘4’: System.out.println(“Division”);
                   break;            
    default: System.out.println(“Invalid option”);
}
 
}

Activity 4-4
Complete the functionality of example 4-4.
After selecting an operation, the user inputs two integers and the program performs the appropriate operation and displays the result.
Filename: ActivityFourDashThree.java

Activity 4-5
Use while-loop to make Activity 4-3 iterative. Processing is to be carried out 5 times.
Filename: ActivityFourDashFive.java

Activity 4-6
Use do-while loop to make Activity 4-4 iterative. Include a fifth option:
[5] Exit. When the user chooses 5, the program displays “Thanks!”.
The program loops until the user chooses 5.

Activity 4-7
Use for-loop to make Activity 4-3 iterative. Processing is to be carried out 5 times.
Filename: ActivityFourDashSeven.java

import java.io.*;
 
public class ActivityFourDashOne 
{
	public static void main(String[]args)
	{
 
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));			            
		System.out.print("Enter your grade: ");
		String grade= br.readLine( );
 
 
	int grade = 0;
if( grade > 75 ) {
System.out.println("You Passed Your grade is " + grade);
 
//System.out.println("Congratulations!");
//System.out.println("You passed!");
}
 
}
}

i can't compile it and i dont know what's missing or wrong

thank you.. just got confused with the codes in my head,,, i'll proceed to the next activity

import java.io.*;
 
public class ActivityFourDashThree {
 
    public static void main(String[] args) throws Exception {
 
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        System.out.print("Enter your magnitude: ");
        double magnitude = br.readLine();
 
        double magnitude = Integer.parseint(magnitude);
      if( magnitude>=10.0)
{
System.out.println("Epic");
System.out.println("Never recorded");
              }
 
else if( magnitude>=9.0 && magnitude<=9.9)
{
System.out.println("Great");
System.out.println("Devastating in areas several thousand miles across.");
 
    }
 
else if( magnitude>=8.0 && magnitude<=8.9)
{
System.out.println("Great");
System.out.println("Can cause serious damage in areas several hundred miles across");
 
    }
	else if( magnitude>=7.0 && magnitude<=7.9)
{
System.out.println("Major");
System.out.println("Can cause serious damage over large areas.");
 
    }
	else if( magnitude>=6.0 && magnitude<=6.9)
{
System.out.println("Strong");
System.out.println("Can be destructive in areas up to about 160 km across.");
 
    }
		else if( magnitude>=5.0 && magnitude<=5.9)
{
System.out.println("Moderate");
System.out.println("Can cause major damage to poorly constructed buildings. ");
 
    }
 
			else if( magnitude>=4.0 && magnitude<=4.9)
{
System.out.println("Light");
System.out.println("Noticeable shaking of indoor items, rattling noises. ");
 
    }
				else if( magnitude>=3.0 && magnitude<=3.9)
{
System.out.println("minor");
System.out.println("Often felt, but rarely causes damage.");
 
    }
					else if( magnitude>=2.0 && magnitude<=2.9)
{
System.out.println("minor");
System.out.println("Generally not felt, but recorded.");
 
    }
						else if( magnitude>=0 && magnitude<=2)
{
System.out.println("micro");
System.out.println("Microearthquakes, not felt.);
 
    }
}

i can't find the error.. is double wrong? or i will use float?

 import java.io.*;
 
public class ActivityFourDashThree {
 
    public static void main(String[] args) throws Exception {
 
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        System.out.print("Enter your magnitude: ");
        double magnitude = br.readLine();
 
        double magnitude = Integer.parseint(magnitude);
      if( magnitude>=10.0)
{
System.out.println("Epic");
System.out.println("Never recorded");
              }
 
else if( magnitude>=9.0 && magnitude<=9.9)
{
System.out.println("Great");
System.out.println("Devastating in areas several thousand miles across.");
 
    }
 
else if( magnitude>=8.0 && magnitude<=8.9)
{
System.out.println("Great");
System.out.println("Can cause serious damage in areas several hundred miles across");
 
    }
	else if( magnitude>=7.0 && magnitude<=7.9)
{
System.out.println("Major");
System.out.println("Can cause serious damage over large areas.");
 
    }
	else if( magnitude>=6.0 && magnitude<=6.9)
{
System.out.println("Strong");
System.out.println("Can be destructive in areas up to about 160 km across.");
 
    }
		else if( magnitude>=5.0 && magnitude<=5.9)
{
System.out.println("Moderate");
System.out.println("Can cause major damage to poorly constructed buildings. ");
 
    }
 
			else if( magnitude>=4.0 && magnitude<=4.9)
{
System.out.println("Light");
System.out.println("Noticeable shaking of indoor items, rattling noises. ");
 
    }
				else if( magnitude>=3.0 && magnitude<=3.9)
{
System.out.println("minor");
System.out.println("Often felt, but rarely causes damage.");
 
    }
					else if( magnitude>=2.0 && magnitude<=2.9)
{
System.out.println("minor");
System.out.println("Generally not felt, but recorded.");
 
    }
						else if( magnitude>=0 && magnitude<=2)
{
System.out.println("micro");
System.out.println("Microearthquakes, not felt.");
 
    }
}
}

this is 2nd try still errors

thanks.. i am very thankful for this site.. i will learn lots of things here..