Unit 3 Boolean Expressions - 3.1

3.1 Boolean Expressions

Java’s relational operators

• equal to: ==
• not equal to: !=
• less than: <
• greater than: >
• less than or equal to: <=
• greater than or equal to >=

Hack!

int myAge = 15;
int otherAge = 45; 

using these integers, determine weather the following statements are True or False

Strings

popcorn hack

whats wrong with this code? (below)

String myName = "Alisha"; // Now "Alisha" is correctly a string

boolean areNamesEqual = myName.equals("Alisha"); // Use .equals for String comparison

if (areNamesEqual) {
    System.out.println("True");
} else {
    System.out.println("False");
}

True

comparison of string objects should be done using String methods, NOT integer methods.

• .equal
• compare to

String myName = "Alisha";
boolean areNamesEqual = myName.equals("Alisha");  

if (areNamesEqual) {
    System.out.println("True");
} else {
    System.out.println("False");
}

homework question

what is the precondition for num?

The number of digits in num must be between 1 and 6, inclusive.

num must be greater than or equal to 0 (num >= 0).