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content/ta/spring2018/cpsc220/feb27.md

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+# Lecture for February 27th
+
+## Review for midterm
+
+Chapter 1 -- Code Style, API
+
+Chapter 2 -- Variables & Assignments, strings
+
+Chapter 3 -- input & output
+
+Chapter 4 -- branches (if, if/else, switch)
+
+Chapter 5 -- loops (while, for), scope
+
+Chapter 6 -- File Reading and Writing
+
+## Separated vs Connected Branches
+
+What is the output of this code?
+
+```java
+String preferredLanguage = "Spanish";
+if (preferredLanguage.equals("Chinese")) {
+    System.out.println("Ni hao!");
+}
+if (preferredLanguage.equals("Spanish")) {
+    System.out.println("Hola!");
+}
+if (preferredLanguage.equals("French")) {
+    System.out.println("Bonjour!");
+}
+if (preferredLanguage.equals("German")) {
+    System.out.println("Gutentag!")
+} else {
+    System.out.println("Hello!")
+}
+```
+
+The output is
+
+```reStructuredText
+Hola!
+Hello!
+```
+
+This is because each of the if statements are independent from each other. Whether or not the if statement gets check is not affected by the if statements around it.
+
+Since the preferred language equals Spanish it outputs `Hola!` But since the language is also *not German* it prints out `Hello!` as well.
+
+
+
+## Using an Array
+
+Square brackets notation is used to access elements, array slots can be used as variables
+
+```java
+int[] array = new int[7]; // Creates an integer array of size 7
+array[0] = 5;
+```
+
+
+
+## Swapping Elements
+
+You can swap `x` and `y` in the following way with a *temporary* variable
+
+```java
+int x = 6;
+int y = 1;
+
+int temp = x;
+
+x = y;
+y = temp;
+```
+
+
+
+## Two-Dimensional Arrays
+
+```java
+// Creates a 2D array of two rows and three columns
+int[][] a = new int[2][3]
+```
+
+You can access an element of this 2D array using the conventional square bracket notation
+
+```java
+a[0][0] = 5;
+```
+