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@@ -1,26 +1,40 @@
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---
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title: cond
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description: "Return one of two arguments, depending on the value of a third argument."
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description: Returns one of two arguments depending on the value of the control argument.
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categories: [functions]
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keywords: [conditional, ternary]
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menu:
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docs:
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parent: functions
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signature: ["cond CONTROL VAR1 VAR2"]
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signature: [cond CONTROL ARG1 ARG2]
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relatedfuncs: [default]
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---
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`cond` returns *VAR1* if *CONTROL* is true, or *VAR2* if it is not.
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Example:
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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.
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```go-html-template
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{{ cond (eq (len $geese) 1) "goose" "geese" }}
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{{ $qty := 42 }}
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{{ cond (le $qty 3) "few" "many" }} → "many"
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```
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Would emit "goose" if the `$geese` array has exactly 1 item, or "geese" otherwise.
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The CONTROL argument must be either `true` or `false`. To cast a non-boolean value to boolean, pass it through the `not` operator twice.
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```go-html-template
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{{ cond (42 | not | not) "truthy" "falsy" }} → "truthy"
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{{ cond ("" | not | not) "truthy" "falsy" }} → "falsy"
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```
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{{% note %}}
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Whenever you use a `cond` function, *both* variable expressions are *always* evaluated. This means that a usage like `cond false (div 1 0) 27` will throw an error because `div 1 0` will be evaluated *even though the condition is false*.
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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.
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In other words, the `cond` function does *not* provide [short-circuit evaluation](https://en.wikipedia.org/wiki/Short-circuit_evaluation) and does *not* work like a normal [ternary operator](https://en.wikipedia.org/wiki/%3F:) that will pass over the first expression if the condition returns `false`.
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[short-circuit evaluation]: https://en.wikipedia.org/wiki/Short-circuit_evaluation
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[ternary operators]: https://en.wikipedia.org/wiki/Ternary_conditional_operator
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{{% /note %}}
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Due to the absence of short-circuit evaluation, these examples throw an error:
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```go-html-template
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{{ cond true "true" (div 1 0) }}
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{{ cond false (div 1 0) "false" }}
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```
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