Ultimate Java Programming Cheatsheet

Java Programming Cheatsheet

Java is one of the most popular, most adopted and general purpose programming language used by millions of developers and billions of devices around the world. It is a class-based, object-oriented language and designed to be portable, which means that you can find it on all platforms, operating systems, and devices. It is used to develop all kinds of Android apps, desktop apps, and video games. It is also commonly used as a server-side language for enterprise-level back end development. This programming language has long-term compatibility and developers are comfortable with Java.

Cheat-sheet for Java Programming is given below:

Java Data Types

byte / short / int / long	10,-30
float / double	88.58
char	‘D’
boolean	true, false
String	“Keep Following Techworm”

Java Data Conversions

String to Number
int i = Integer.parseInt(str);
double d = Double.parseDouble(str);

Any Type to String
String s = String.valueOf(value);

Numeric Conversions
int i = (int)

Java Arithmetic Operators

x + y	add	x – y	subtract
x * y	multiply	x / y	divide
x % y	modulus	++x / x++	increment
		–x / x–	decrement

Java Comparison Operators

x < y	Less	x <= y	Less or eq
x > y	Greater	x >= y	Greater or eq
x == y	Equal	x != y	Not equal

Java Boolean Operators

! x (not)

x && y (and)

x || y (or)

Java Text Formatting

printf style formatting
System.out.printf(”Count is %d\n”, count);
s = String.format(“Count is %d”, count);MessageFormat style formatting
s = MessageFormat.format(
”At {1,time}, {0} Runs Scored.”,
25, new Date());Individual Numbers and Dates
s = NumberFormat.getCurrency()
.format(x);
s = new SimpleDateFormat(“”yyyy/mm/dd””)
.format(new Date());

Java Hello World

public class HelloWorld {

    public static void main(String[] args) {
        System.out.println("Hello, World");
    }

}

Java String Methods

s.length()	length of s
s.charAt(i)	extract ith character
s.substring(start, end)	substring from start to end-1
s.toUpperCase()	returns copy of s in ALL CAPS
s.toLowerCase()	returns copy of s in lowercase
s.indexOf(x)	index of first occurence of x
s.replace(old, new)	search and replace
s.split(regex)	splits string into tokens
s.trim()	trims surrounding whitespace
s.equals(s2)	true if s equals s2
s.compareTo(s2)	0 if equal/+ if s > s2/- if s < s2

Java Statements

If Statement
if ( expression ) {
statements
} else if ( expression ) {
statements
} else {
statements
}While Loop
while ( expression ) {
statements
}Do-While Loop
do {
statements
} while ( expression );For Loop
for ( int i = 0; i < max; ++i) {
statements
}For Each Loop
for ( var : collection ) {
statements
}Switch Statement
switch ( expression ) {
case value:
statements
break;
case value2:
statements
break;
default:
statements
}Exception Handling
try {
statements;
} catch (ExceptionType e1) {
statements;
} catch (Exception e2) {
catch-all statements;
} finally {
statements;
}

There are 2 comments 2 comments

Ali Tama 10 months ago

I love the cheat sheet. I find it very interesting. It presents a whole Java text. I have read several Java text but this is a template for people like us. Complete it showing us how each is used, when to use and how to use them

Ghanta 10 months ago

What the fucking holy shit is this?????
fuck u and fuck your bullshit site