# Armstrong Number # Armstrong Number

### Write a php program to find the number is an Armstrong Number or not

If the sum of the cubes of the digits of a number is equal to the number then its called an Armstrong number .

Eg:- 153
(1*1*1)+(5*5*5)+(3*3*3) = 1+125+27 = 153

#### Program :

``````<?php
\$num=153;
\$sum=0;
\$num_copy=\$num;
while(\$num!=0)
{
\$rem=\$num%10;
\$sum=\$sum+\$rem*\$rem*\$rem;
\$num=\$num/10;
}
if(\$num_copy==\$sum)
{
echo "Yes \$num_copy is an Armstrong number";
}
else
{
echo "No \$num_copy is not an Armstrong number";
}
?>  ``````
1. Define a number which you want to find Armstrong or not to \$num
2. Declare a variable \$sum=0
3. Copy the \$num to a new variable for checking whether the it is Armstrong or not
4. Loop the \$num until its not 0
5. Get the reminder of \$num by \$num%10
6. Find the sum of cube of the reminder and add it with \$sum
7. Divide the \$num by 10
8. If the \$num_copy ==\$sum then the number is Armstrong

#### Logic :

\$num = 153
\$num_copy = \$num, ie; \$num_copy = 153

1st loop
\$sum = 0
while(153!=0)
{
\$rem = \$num%10 = 153 % 10 = 3
\$sum = \$sum+\$rem * \$rem * \$rem = 0 + 3*3*3 = 0+27 = 27
\$num = \$num/10 = 153/10= 15
}

2nd loop
\$sum = 27
while(15!=0)
{
\$rem = \$num%10 = 15 % 10 = 5
\$sum = \$sum+\$rem * \$rem * \$rem = 27 + 5*5*5 = 27+125 = 152
\$num = \$num/10 = 15/10= 1
}

3rd loop
\$sum = 152
while(1!=0)
{
\$rem = \$num%10 = 1 % 10 = 1
\$sum = \$sum+\$rem * \$rem * \$rem = 152 + 1*1*1 = 152+1 = 153
\$num = \$num/10 = 1/10= 0.1
}

Note : When we give the variable directly in the ” “, it will display the value of that variable. 