Contents

Strings in Java

Let’s look at some basic String operations in Java.

String s = "Almost summer break";

s.substring(0,3)

s.substring(4,7)

s.toUpperCase()

s.toLowerCase()

String[] array = s.split(" ")

System.out.println(array)

System.out.println(Arrays.toString(array))

for (String s : array) { 
    System.out.println(s); 
}

ArrayLists

ArrayLists are the functional equivalent of Lists in Python. See some sample usage cases below.

ArrayList<String> alist=new ArrayList<String>();  
alist.add("Jeannie");
alist.add("Rohit");
alist.add("Lida");
alist.add("Steve");
alist.add("Dan");
alist.add("Sam");

System.out.println(alist)  // print the list 

alist.add(3, "Iris") // add Rohit to index 3

System.out.println(alist)

alist.get(2) // get the element at index 2

// set index 5 to Steve (returns old value)
alist.set(5, "Steve")  

System.out.println(alist)

Arrays

import java.util.Arrays;

String [] myList = new String[6];

String [] myList = {"Jeannie", "Rohit", "Lida", "Steve", "Dan", "Sam"};

System.out.println(Arrays.toString(myList));

System.out.println(myList[2])

myList[4] = "Aaron"

System.out.println(Arrays.toString(myList))

int [] myList = new int[3]

System.out.println(Arrays.toString(myList))

String [] myList = new String[6];
System.out.println(Arrays.toString(myList))