| | 1 | The '''if''' expression evaluates to exactly one of two expressions based on a condition. |
| | 2 | |
| | 3 | === Grammar === |
| | 4 | {{{ |
| | 5 | if(<condition>, <texpr>, <fexpr>) |
| | 6 | }}} |
| | 7 | |
| | 8 | If the '''condition''' is true, '''texpr''' is evaluated; otherwise '''fexpr''' is evaluated. The condition is always evaluated and subsequently '''texpr''' or '''fexpr''' will be unless condition threw an exception. |
| | 9 | |
| | 10 | The type of the '''if''' expression is the greatest common denominator between the type of '''texpr''' and the type of '''fexpr'''. |
| | 11 | |
| | 12 | Note that using '''if''' expressions to check for '''nil''' is uncommon, since there is a coalesce operator for that purpose which is more succinct and avoids double evaluation. |
| | 13 | |
| | 14 | {{{ |
| | 15 | #!cobra |
| | 16 | # Example 1 |
| | 17 | print if(x>y, x, y) |
| | 18 | |
| | 19 | # Example 2 |
| | 20 | print if(value, 'yes', 'no') # type is String |
| | 21 | |
| | 22 | # Example 3 |
| | 23 | total += if(direction==DirectionEnum.Long, +1, -1) * amount |
| | 24 | |
| | 25 | # Example 4 |
| | 26 | foo = if(condition, 'x', nil) # type is String? |
| | 27 | |
| | 28 | # Example 5 |
| | 29 | foo = if(condition, 'x', 5) # type is Object |
| | 30 | }}} |
