This version is out of date, covering development from v9.5.0 to v9.7.3. It is maintained here only for inbound reference links from elsewhere. It is no longer actively updated.

Jump to the current version of aTbRef

Tinderbox v9 Icon


Operator Type: 

Operator Scope of Action: 

Operator Purpose: 

Operator First Added: 

Operator Last Altered: 

Operator Has Newer Dot-Operator Variant: 

 Function  [other Function type actions]

 Item  [operators of similar scope]

 Mathematical  [other Mathematical operators]


 As at baseline



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);