Operator Type:
Operator Scope of Action:
Operator Purpose:
Data Type Returned:
Operator First Added:
Operator in Current Baseline:
Operator Last Altered:
Operator Has Newer Dot-Operator Variant:
Function [other Function type actions]
Item [operators of similar scope]
Mathematical [other Mathematical operators]
Number [about Number data type]
v4.0.0
Baseline
As at baseline
Yes
round(sourceNum)
round() rounds the value of its sourceNum argument to the nearest integer. Note that from v9.5.2, there is now a dot-operator version (with the same behaviour) Number.round().
The Number.format, Number.precision and format() functions all round numbers in this manner when shortening numbers during formatting. A partial integer over .50 always round up, everything else rounds down. Thus:
$MyNumber = round(4.0);
gives 4
$MyNumber = round(4.2);
gives 4
$MyNumber = round(4.5);
gives 5
$MyNumber = round(4.7);
gives 5
The round function with work on string literal or String attribute values that are just numbers:
$MyNumber = round("4.2");
gives 4
$MyNumber = round("4.7");
gives 5
$MyString = round(4.2);
gives "4"
$MyString = round(4.7);
gives "5"
$MyString = round("4.2");
gives "4"
$MyString = round("4.7");
gives "5"
There are also functions to always force rounding upwards (ceiling)—see ceil(), or to force rounding downwards (floor)—see floor().
For a practical example, assume you would like to round you calculation (upward) to the nearest 100, so if the calculation output is 167 it should be 200, for a result of 540 a result of 600, and so on. This can be done like so:
$MyNumber = 100*ceil($MyNumber/100);
whereas if you used round(), as in:
$MyNumber = 100*round($MyNumber/100);
the result would vary depending on whether $MyNumber started above or below the nearest 50. An opposite of the first example, i.e. where everything rounds downwards to the nearest 100 can be done using floor():
$MyNumber = 100*floor($MyNumber/100);
See also—notes linking to here: