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diff --git a/docs/content/en/functions/compare/Cond.md b/docs/content/en/functions/compare/Cond.md new file mode 100644 index 000000000..4b92a893c --- /dev/null +++ b/docs/content/en/functions/compare/Cond.md @@ -0,0 +1,47 @@ +--- +title: compare.Conditional +linkTitle: cond +description: Returns one of two arguments depending on the value of the control argument. +categories: [functions] +keywords: [] +menu: + docs: + parent: functions +function: + aliases: [cond] + returnType: any + signatures: [compare.Conditional CONTROL ARG1 ARG2] +relatedFunctions: + - compare.Conditional + - compare.Default +aliases: [/functions/cond] +--- + +The CONTROL argument is a boolean value that indicates whether the function should return ARG1 or ARG2. If CONTROL is `true`, the function returns ARG1. Otherwise, the function returns ARG2. + +```go-html-template +{{ $qty := 42 }} +{{ cond (le $qty 3) "few" "many" }} → "many" +``` + +The CONTROL argument must be either `true` or `false`. To cast a non-boolean value to boolean, pass it through the `not` operator twice. + +```go-html-template +{{ cond (42 | not | not) "truthy" "falsy" }} → "truthy" +{{ cond ("" | not | not) "truthy" "falsy" }} → "falsy" +``` + +{{% note %}} +Unlike [ternary operators] in other languages, the `cond` function does not perform [short-circuit evaluation]. The function evaluates both ARG1 and ARG2, regardless of the CONTROL value. + +[short-circuit evaluation]: https://en.wikipedia.org/wiki/Short-circuit_evaluation +[ternary operators]: https://en.wikipedia.org/wiki/Ternary_conditional_operator +{{% /note %}} + + +Due to the absence of short-circuit evaluation, these examples throw an error: + +```go-html-template +{{ cond true "true" (div 1 0) }} +{{ cond false (div 1 0) "false" }} +``` |