Some Random java fun.txt

Reverse an Array in Java

Collections.reverse(Arrays.asList(array));


Sum a List of Numbers

IntStream.range(1, 1000).sum();

2)Check if a String contains at least one of the given keyword

List<String> wordList = Arrays.asList("java", "feature", "love");
		String str = "Dummy text. Java 8 has powerful features";
System.out.println(wordList.stream().anyMatch(str::contains));

3)Copy file from One location to another

Files.copy(Paths.get("/data/text/file.txt"),Paths.get

4)Binary representation of number n

Integer.toBinaryString(int n);

5)Executing a commented Code

// \u000d System.out.println("comment executed"); 

6)Make a collection unmodifiable

public static final Collection secret=
Collections.unmodifiableCollection(Arrays.asList("Jimmy","Carter","JOhn") );

7)Faster Multiplication and Division

n = n << 1;  // Multiply n with 2 
n = n >> 1;  // Divide n by 2
 
8)Sort an Array

Arrays.sort(arrayReference);

9)Input a character using Scanner

char c = sccanner.next().charAt(0);



Let double K = Math.log10(N);
now K = K - Math.floor(K);
int X = (int)Math.pow(10, K);
X will be the most significant digit.



No. of digits in N = Math.floor(Math.log10(N)) + 1;







Splitting String to words

use String.split("  ");