# Project Euler Example 2 using PHP In project Euler example 2 the question is very simple:

Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:

1, 2, 3, 5, 8, 13, 21, 34, 55, 89, …

By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

Now to find a Fibonacci sequence

``````function fabonnaciNumber()
{
\$a = 1;
\$b = 1;
\$sum = 0;
\$c = \$a + \$b;
while(\$c < 4000000){
if(\$c % 2 == 0){
\$sum += \$c; // \$sum = \$sum + \$c;
\$a = \$b + \$c;
\$b = \$a + \$c;
\$c = \$a + \$b;
}
}
echo \$sum;
}

echo fabonnaciNumber();``````

In this function, the variable \$a is initialized with value 1 and \$b is also initialized with the value 1. We need to store the sum and make sure the value is not exceeding 4000000. so we have to create a new variable called \$sum initialized with value 0. Create another variable called \$c = \$a + \$b; which holds the sum value of \$a and \$b.\

Now run a while loop that has a maximum iteration value of 4000000. check if the number is perfectly divisible by 2 then sum the value of \$c into \$sum and update the value of \$a, \$b, and \$c.