gohugoio/hugo · error

Floor operator can't be used with non-float value

Error message

Floor operator can't be used with non-float value

What it means

Thrown by math.Floor (tpl/math/math.go:129) when its argument cannot be converted to float64. Floor returns the greatest integer <= n and needs a float-convertible input.

Solutions

1. Pass a numeric value to math.Floor.
2. Add a numeric default: {{ math.Floor (.Param "n" | default 0) }}.
3. Guard behind a numeric check on the source value.
4. Fix the source data so the field is numeric.

Example fix

// before
{{ math.Floor .Params.score }}

// after
{{ $n := .Params.score | default 0 }}
{{ math.Floor $n }}

// Validate numeric input before math.Floor:
{{ $v := .Param "n" | default 0 }}
{{ math.Floor $v }}

// Reuse the isNumeric guard from errorIndex 148 before calling math.Floor.

When it happens

Trigger: Calling {{ math.Floor .Value }} with a non-numeric string, nil, bool, struct, or slice.

Common situations: Unset param (nil); text field where a number was expected; quoted numeric string that fails conversion.

Related errors

• Ceil operator can't be used with non-float value
• Log operator can't be used with non integer or float value
• modulo operator can't be used with non integer value
• requires a numeric argument
• requires numeric arguments

AI-assisted analysis of gohugoio/hugo@52c9bd7908 (2026-08-09). Data as JSON: /api/errors/173f2e785cef5b1b. Report an issue: GitHub.

Appendix: source

Thrown at tpl/math/math.go:129

// Cos returns the cosine of the radian argument n.
func (ns *Namespace) Cos(n any) (float64, error) {
	af, err := cast.ToFloat64E(n)
	if err != nil {
		return 0, errors.New("requires a numeric argument")
	}
	return math.Cos(af), nil
}

// Div divides n1 by n2.
func (ns *Namespace) Div(inputs ...any) (any, error) {
	return ns.doArithmetic(inputs, '/')
}

// Floor returns the greatest integer value less than or equal to n.
func (ns *Namespace) Floor(n any) (float64, error) {
	xf, err := cast.ToFloat64E(n)
	if err != nil {
		return 0, errors.New("Floor operator can't be used with non-float value")
	}

	return math.Floor(xf), nil
}

// Log returns the natural logarithm of the number n.
func (ns *Namespace) Log(n any) (float64, error) {
	af, err := cast.ToFloat64E(n)
	if err != nil {
		return 0, errors.New("Log operator can't be used with non integer or float value")
	}

	return math.Log(af), nil
}

// Max returns the greater of all numbers in inputs. Any slices in inputs are flattened.
func (ns *Namespace) Max(inputs ...any) (maximum float64, err error) {
	return ns.applyOpToScalarsOrSlices("Max", math.Max, inputs...)

View on GitHub (pinned to 52c9bd7908)