NewSourceMedia Blog » Math and Numbers

PHP how to find Odd and Even numbers

admin — Tue, 30 Nov 1999 06:00:00 +0000

Here is how to find odd and even numbers in php. How to find if a number is odd or even? In PHP I learn to use the MOD (%) operator. see below for an example: $i = 10;

if ($i % 2) {
echo "$i is odd";
} else {
echo "$i is even";
}

You can also use the PHP "&" operator that will give you better performance You can use the PHP code like so:

$i = 10;
if ( $i&1 )
{
echo "$i is odd";
}
else
{
echo "$i is even";
}

PHP Leading Zero for Double Digit Numbers

admin — Tue, 30 Nov 1999 06:00:00 +0000

How to output a number with leading zero like dates and time. Question: In php, how do I format my numbers so that all numbers have a double digit. I am displaying the number of days in a month and have to match the date formatted for day. Answer: Just check the number value during a loop in php to see if it's less then 10. Php code is below: If so then add the leading zero to your string.

$day";
?>

PHP Validation Numbers Only From

admin — Tue, 30 Nov 1999 06:00:00 +0000

How to check for number values only and block or convert letter strings to integers. Question: How to validate number values to and block all letters and symbol in a form. Answer: You can check the value or convert the value to an integer (number). 1) Check a value using is_int() to finds whether the given variable is an integer 2) Note: To test if a variable is a number or a numeric string (such as form input, which is always a string), you must use is_numeric(). 3) Convert the value to an integer (number) using settype.



settype($foo, "integer"); // $foo is now 5 (integer)
settype($bar, "string"); // $bar is now "1" (string)
?>

or you can use int to do the trick.



PHP Round Off Decimal or Convert to Decimal Point
admin — Sun, 11 Jul 2004 00:22:11 +0000
Round a number up or down or Round off a floating decimal point number using PHP's functions round(). Or convert a digit to a decimal point. Greate for shopping carts or time sheet programs.

Round Off Decimal

Round a number up or down or Round off a floating decimal point number using PHP's functions round().

Example. round();
 echo round(3.4); // 3
echo round(3.5); // 4
echo round(3.6); // 4
echo round(3.6, 0); // 4
echo round(1.95583, 2); // 1.96
echo round(1241757, -3); // 1242000
echo round(5.045, 2); // 5.05
echo round(5.055, 2); // 5.06
?>

Convert to Decimal Point

Example. number_format();
 $number = "28";
$number = number_format($number, 2);
echo $number; // equals "28.00"
?>

For a good book on PHP, check out Beginning PHP4