# Java: Find a missing number in an array

## Java Array: Exercise-24 with Solution

Write a Java program to find a missing number in an array.

**Pictorial Presentation:**

**Sample Solution**:

**Java Code:**

```
// Import the java.util package to use utility classes, including Scanner.
import java.util.*;
// Define a class named Exercise24.
public class Exercise24 {
// The main method for executing the program.
public static void main(String[] args) {
// Declare variables for total number and an array of integers.
int total_num;
int[] numbers = new int[]{1, 2, 3, 4, 6, 7};
// Assign the value 7 to the variable total_num.
total_num = 7;
// Calculate the expected sum of numbers using the arithmetic sum formula.
int expected_num_sum = total_num * ((total_num + 1) / 2);
// Initialize a variable to store the sum of numbers.
int num_sum = 0;
// Iterate through the elements of the 'numbers' array.
for (int i : numbers) {
// Add each element to the 'num_sum' variable.
num_sum += i;
}
// Calculate the missing number by subtracting 'num_sum' from 'expected_num_sum'.
System.out.print(expected_num_sum - num_sum);
// Print a newline character to end the line.
System.out.print("\n");
}
}
```

Sample Data: 1,2,3,4,6,7

Sample Output:

5

**Flowchart: **

**Java Code Editor:**

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