7 PM – Intro To Java – Roland

Today We Did

1. Learned about &&, ||, !=, and !
   1. && = And
   2. || = Or
   3. != –> not equals (primitives)
   4. ! –> negate
2. .equals() and .equalsIgnoreCase()
3. Lists in Java
   1. List<String> names = new ArrayList<>();
   2. Adding to a list: names.add(“name”);
   3. Getting from a list: names.get(0);
   4. Modifying a list: names.set(0, “new_name”);
   5. Inserting into a list: names.add(1, “second_name”);
   6. Size of list: names.size();
   7. Looping through a list: for (String n: names) {…}

Homework

1. Create a new Java file March27_AndOrListHW.java
2. Complete the following exercises:
   1. Write a new Java program that will ask the user for the grade they got on their exam (which is an integer)
      1. If the number is between 60 to 70, print “Your grade is D”. You have to use AND (&&).
      2. If the number is between 70 to 80, print “Your grade is C”. You have to use AND (&&).
      3. If the number is between 80 to 90, print “Your grade is B”. You have to use AND (&&).
      4. If the number is between 90 to 99, print “Your grade is A”. You have to use AND (&&)
      5. If the number is equal to 100, print “Your grade is A+, good job”.
   2. Write a new Java program that will create a List of String and add all of these colors: red, green, blue, purple, yellow, orange. ([“red”, “green”, “blue”, “purple”, “yellow”, “orange”])
   3. Use for loop to go through each color inside the above list and print all colors to the shell.
      1. If the color is “blue”, print “blue is my favorite color”. If the color is “yellow”, print “I don’t like yellow color.
      2. For everything else, just print the color name.
      3. The result should be like below

      4. red
         green
         Blue is my favorite color
         purple
         I don't like yellow
         orange

3. Upload your answer to google drive before next week Tuesday night.

If you have any questions feel free to email me rolandyang@ayclogic.com

Feel free to reference the code in the notes if you are lost (March27_AndOrList.java): https://drive.google.com/drive/folders/10JdSDu9bC5k_Jewi3BxazkkuBNrrVpqA?usp=sharing