Math Functions

Arithmetic in Jess is a language form, not a function. Wrap the expression in $( … ) and Jess evaluates it, preserving node types (dimensions keep their unit; colors stay colors).

op() is retired

Pre-2.x Jess spelled arithmetic op(2px * 3) and required importing op from @jesscss/fns. That function no longer exists — it is not in the package and not in the Jess built-in function set. Use $( … ) instead; nothing needs importing.

Example

$myDimension: 3px;

.box {
  one: $(2px * 3);
  two: $(2px * 3 * 2);
  three: $($myDimension * 3);
  color: $(#333 * 2);
}

Output:

.box {
  one: 6px;
  two: 12px;
  three: 9px;
  color: #666666;
}

info

Only what you put inside $( … ) is evaluated. Everything else is preserved verbatim.

Not yet implemented

Parenthesized sub-groups inside $( … ) — $(2px * (2 + 1)) — are not accepted by the current parser. Split the expression, or precompute the group into a variable, until grouping lands.

See Expressions for operator precedence, unit conversion, and division rules.

Example​

Example