| [TOC](Readme.md) [Prev](fieldcomp.md) [Next](coalesce.md) | |
| _Expressions_ | |
| # Conditional Fields | |
| Field comprehensions can also be used to | |
| add a single field conditionally. | |
| Converting the resulting configuration to JSON results in an error | |
| as `justification` is required yet no concrete value is given. | |
| <!-- CUE editor --> | |
| ``` | |
| price: float | |
| // Require a justification if price is too high | |
| justification: string if price > 100 | |
| price: 200 | |
| ``` | |
| <!-- result --> | |
| ``` | |
| price: 200 | |
| justification: string | |
| ``` |