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int number = 4;
number++ // equal to number += 1 or number = number + 1

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String name = "Azka Purba"; // literal string

String name = new String("Azka Purba"); // object string

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String name = "Azka";
int age = 22;
String formattedString = String.format(
	"My Name is %s, Im %d years old", // %f for double, %b for boolean
	name, 
	age
);
System.out.println(formattedString)

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char vowels[] = new char[5]; // create new array containing char with the length of 5

// or
char vowels[] = {'a', 'i', 'u', 'e', 'o'};

Array.toString(vowels);
Array.sort(vowels);

char key = 'o';
int foundItemIndex = Arrays.binarySearch(vowels, key);


// other
Arrays.fill(vowels, "x") // replace all elements with "x"
char copyOfVowels[] = Arrays.copyOf(vowels, vowels.length);

int startingIndex = 1;
int endingIndex = 4;
char copyOfVowels[] = Arrays.copyOfRange(vowels, startingIndex, endingIndex);

vowels == copyOfVowels // will return false because it's a different object
Arrays.equals(vowels, copyOfVowels) // to compare it's value

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// string method
.length()
.isEmpty()
.toUpperCase()
.toLowerCase()
.replace()
.contains()

// comparing between String object
string1.equals(string2)