An example on adding all the elements in an array that user gives. A really simple logic involving 2 main steps.
Tips:
You can also use n instead of a.length
sum+=a[i] is equal to sum=sum+a[i]
Similarly you can apply this logic for other data types also. If you apply for a char, a string will be resulted if you apply for a string concatenation will be done and might appear as a sentence. For other numeric data types like long,float,double etc, you'll get the sum.
n=5: No. of elements to be added are 5
sum=0: Initially the sum of all the elements is 0.
a[i]=s.nextInt(): Initially at first i=0, afterwards i increments.
a[0]=1
0=0+1 = 1 => sum=1
a[1]=2
1=1+2 = 3 => sum=3
a[2]=3
3=3+3 = 6 => sum=6
a[3]=4
6=6+4 = 10 => sum=10
a[4]=5
10=10+5 = 15 => sum=15
End of loop. Control comes out. The value in sum (15) will be printed.
Add all Elements in Array
import java.util.*;
class SumArray
{
public static void main(String args[])
{
// Create a Scanner object for taking input from cmd
Scanner s=new Scanner(System.in);
// Take the no.of elements that user want to sum
int n=s.nextInt();
// Create an array of given size (n)
int[] a=new int[n];
// Initialize sum to 0
int sum=0;
// Loop till end of array
for(int i=0;i<a.length;i++)
{
// Read int from user and store it in each element
a[i]=s.nextInt();
// Sum every element that user gives and store it in sum
sum+=a[i];
}
System.out.println("The sum of all the elements is "+sum);
}
}
Output
5
1
2
3
4
5
The sum of all the elements is 15
Tips:
You can also use n instead of a.length
sum+=a[i] is equal to sum=sum+a[i]
Similarly you can apply this logic for other data types also. If you apply for a char, a string will be resulted if you apply for a string concatenation will be done and might appear as a sentence. For other numeric data types like long,float,double etc, you'll get the sum.
Analysis
n=5: No. of elements to be added are 5
sum=0: Initially the sum of all the elements is 0.
a[i]=s.nextInt(): Initially at first i=0, afterwards i increments.
a[0]=1
0=0+1 = 1 => sum=1
a[1]=2
1=1+2 = 3 => sum=3
a[2]=3
3=3+3 = 6 => sum=6
a[3]=4
6=6+4 = 10 => sum=10
a[4]=5
10=10+5 = 15 => sum=15
End of loop. Control comes out. The value in sum (15) will be printed.