add number with string concatination problem

1). I have 4 numbers to add up and display result with a string concate to them

For example
$first_number = 10;
$second_number = 20;
$third_number = 30;
$fourth_number = 40;
$direct_text = 'addition of 4 numbers is = ';

I have to display

Print(‘addition of 4 numbers is =’. $first_number + $second_number +$third_number + $fourth_number);

But the concated sing is not displayed also the last variable ($first_number) is not added to string I mean resuld should like this

addition of 4 numbers is = 100

but result is

90

neither the prefixed string nor the last value after dot oprator is added in the result


If I remove the concated string and dot then the addition is correct I mean correct result

Also when I do the add operation in a variable and then concate it to the string then the result is correct

I mean when the is like this

$first_number = 10;
$second_number = 20;
$third_number = 30;
$fourth_number = 40;
$total = $first_number + $second_number +$third_number + $fourth_number;
$direct_text = 'addition of 4 numbers is = ';
print($direct_text . $total);


then result is as required. I mean it is


addition of 4 numbers is = 100

but I want to know that why when we do addition in the same code where concate the string then it not work properly

kindly let me know

 

Use this;

Print('addition of 4 numbers is ='. ($first_number + $second_number + $third_number + $fourth_number));

PHP:

 

Thanks for reply it is really working now.

But i want to know the reason why the number are not added correctly and not displaying string when not enclosing in the parenthesis i just want to know the logic behind it

 

A word of caution - the dot operator has the same precedence as + and -, which can yield unexpected results.

Example:

<php
$var = 3;

echo "Result: " . $var + 3;
?>

The above will print out "3" instead of "Result: 6", since first the string "Result3" is created and this is then added to 3 yielding 3, non-empty non-numeric strings being converted to 0.

To print "Result: 6", use parantheses to alter precedence:

<php
$var = 3;

echo "Result: " . ($var + 3);
?>

 

Thanks so much i now completly solve the issue as well get the reason of error ur answer are very informative thanks again

 

no problem =)