# Lucky Seven Problem in Java

In this Java tutorial, we will learn how to solve lucky seven problem in Java. We will also take a look at the code snippet with the output.

## Problem Statement – Solve Lucky Seven problem in Java

In the problem, we are provided with a number. We have to find the total count of digit 7 in the number.

Example: The number is 7487 so, the total count of digit 7 in the number is 2.

### Integer to String Conversion in Java

** Syntax :- Integer.toString( number ) ;**

from this expression number will be converted into String .

### String to Character Array Conversion in Java

**Syntax:- String.toCharArray () ;**

from this expression String will be converted to character array.

Also, learn,

**Guess The Number Game Using Java with Source Code****Program to find all distinct solutions to N-Queens problem in Java**

### Algorithm to solve lucky seven problem in Java

- Scan a number n .
- Convert the number to String using Integer.toString() .
- Convert String to character array using String.toCharArray() .
- Now, check for each character in CharArray formed if it is ‘7’ increment count.
- Finally, print the count.

### Java Code to count the total occurrence of digit 7 in a given number

import java.util.Scanner; public class Codespeedy { public static void count ( int n ) { String str = Integer.toString(n); char [] s = str.toCharArray(); int count=0; for( int i=0 ; i<s.length ; i++ ) { if ( s[i]=='7') { count++; } } System.out.println(count); } public static void main ( String[] args ) { Scanner scan = new Scanner ( System.in); int n; n = scan.nextInt(); count(n); } }

**INPUT**

7657347

**OUTPUT**

3

In the given number 7 occurs 3 times so, the output is 3.

Also learn,

**Tower of Hanoi Problem using recursion in Java****FizzBuzz Problem In Java- A java code to solve FizzBuzz problem**

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