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| _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 --> | |
| _conditional.cue:_ | |
| ``` | |
| price: number | |
| // Require a justification if price is too high | |
| justification: string if price > 100 | |
| price: 200 | |
| ``` | |
| <!-- result --> | |
| `$ cue eval conditional.cue` | |
| ``` | |
| price: 200 | |
| justification: string | |
| ``` |