In this tutorial, you shall learn about Arithmetic Subtraction Operator in PHP, its syntax, and how to use this operator in PHP programs, with examples.

PHP Subtraction

PHP Arithmetic Subtraction Operator takes two numbers as operands and returns the difference of second operand from first operand.

Symbol

- symbol is used for Subtraction Operator.

Syntax

The syntax for subtraction operator is

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operand_1 - operand_2

The operands could be of any numeric datatype, integer or float.

If the two operands are of different datatypes, implicit datatype promotion takes place and value of lower datatype is promoted to higher datatype.

Examples

1. Subtraction of Integers

In the following example, we take integer values in $x and $y, and find $x - $y using Arithmetic Subtraction Operator.

PHP Program

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<?php
  $x = 5;
  $y = 4;

  $output = $x - $y;

  echo "x = $x" . "<br>";
  echo "y = $y" . "<br>";
  echo "x - y = $output";
?>

Output

PHP Subtraction of Integers

2. Subtraction of Float Values

In the following example, we take floating point values in $x and $y, and find $x - $y using Arithmetic Subtraction Operator.

PHP Program

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<?php
  $x = 5.1;
  $y = 4.2;

  $output = $x - $y;

  echo "x = $x" . "<br>";
  echo "y = $y" . "<br>";
  echo "x - y = $output";
?>

Output

PHP Subtraction of Floats

3. Subtraction of Integer and Float Values

In the following example, we take integer value in $x and floating point value in $y, and find $x - $y using Arithmetic Subtraction Operator.

Since float is higher datatype among integer and float, the output is float.

PHP Program

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<?php
  $x = 5;
  $y = 4.2;

  $output = $x - $y;

  echo "x = $x" . "<br>";
  echo "y = $y" . "<br>";
  echo "x - y = $output";
?>

Output

PHP Subtraction of Integer and Float

Conclusion

In this PHP Tutorial, we learned how to use Arithmetic Subtraction Operator to find the subtraction of given two numbers.