11/3 Class Notes

Today in class, we started off by talking about the difference between strings and characters. Characters just store one character at a time but strings are made up of multiple characters. Each character has an integer it corresponds to. You can see which character corresponds to what integer here: https://www.asciitable.com/

Concatenation means combining different things into one string. The operation we use for this is a plus sign (+).

For example,

String a = "Hello";

char b = 'a';

int c = 1;

System.out.println(a + b + c);

would print out "Helloa1".

We also learned about other string operations.

• String length and index: length()

• A character of a string: charAt():

• Substrings: substring()

• Search for a substring: indexOf(), lastIndexOf(), contains()

• Comparing strings: compareTo()

For example,

String a = "Hello World";

System.out.println(a.length()); //This will print out "11"

System.out.println(a.charAt(2)); //This will print out "l"

System.out.println(a.substring(1, 4); //This will print out "ell"

System.out.println(a.indexOf("Hello")); //This will print out "0"

System.out.println(a.lastIndexOf("l")); //This will print out "9"

System.out.println(a.contains("World")): //This will print out "true"

Here are some methods to compare strings:

• boolean equals()

• boolean equalsIgnoreCase()

• int compareTo()

• int compareToIgnoreCase()

• trim()

• toUpperCase()

• toLowerCase()

Here's the homework for this week: https://docs.google.com/forms/d/e/1FAIpQLSf6_GW5MSvlQv6rjZsBrOsT2P7xHRcDE_V6Z69J7jWWqmEYiw/viewform?usp=sf_link