BcMath\Number::sub

Subtracts an arbitrary precision number

&reftitle.description; public `BcMath\Number` `BcMath\Number::sub` ``BcMath\Number``string``int```num` ``int``null```scale`&null;

Subtracts `num` from `$this`.

&reftitle.parameters;

`num`

- The value to subtract.

&reftitle.returnvalues;

Returns the result of subtraction as a new `BcMath\Number` object.

When the `BcMath\Number::scale` of the result object is automatically set, the greater `BcMath\Number::scale` of the two numbers used for subtraction is used.

&reftitle.examples;

### `BcMath\Number::sub` example when `scale` is not specified

    <?php
    $number = new BcMath\Number('1.234');

    $ret1 = $number->sub(new BcMath\Number('2.34567'));
    $ret2 = $number->sub('-3.456');
    $ret3 = $number->sub(7);

    var_dump($number, $ret1, $ret2, $ret3);
    ?>

&example.outputs;

    object(BcMath\Number)#1 (2) {
      ["value"]=>
      string(5) "1.234"
      ["scale"]=>
      int(3)
    }
    object(BcMath\Number)#3 (2) {
      ["value"]=>
      string(8) "-1.11167"
      ["scale"]=>
      int(5)
    }
    object(BcMath\Number)#2 (2) {
      ["value"]=>
      string(5) "4.690"
      ["scale"]=>
      int(3)
    }
    object(BcMath\Number)#4 (2) {
      ["value"]=>
      string(6) "-5.766"
      ["scale"]=>
      int(3)
    }

### `BcMath\Number::sub` example of explicitly specifying `scale`

    <?php
    $number = new BcMath\Number('1.234');

    $ret1 = $number->sub(new BcMath\Number('2.34567'), 1);
    $ret2 = $number->sub('-3.456', 10);
    $ret3 = $number->sub(7, 0);

    var_dump($number, $ret1, $ret2, $ret3);
    ?>

&example.outputs;

    object(BcMath\Number)#1 (2) {
      ["value"]=>
      string(5) "1.234"
      ["scale"]=>
      int(3)
    }
    object(BcMath\Number)#3 (2) {
      ["value"]=>
      string(4) "-1.1"
      ["scale"]=>
      int(1)
    }
    object(BcMath\Number)#2 (2) {
      ["value"]=>
      string(12) "4.6900000000"
      ["scale"]=>
      int(10)
    }
    object(BcMath\Number)#4 (2) {
      ["value"]=>
      string(2) "-5"
      ["scale"]=>
      int(0)
    }

&reftitle.seealso;

- `bcsub`
- `BcMath\Number::add`