try

Attempts to evaluate an expression and prevents a failure during this evaluation from stopping all subsequent evaluation.

Syntax

• try(expr[, errexpr])

  • expr is an expression

  • errexpr is an expression

Description

Normally, if an error is raised during evaluation of an expression, all evaluation is immediately terminated and the error message is returned. The try function allows you to override this behaviour.

try(expr) evaluates expr and if expr returns an error, try converts this error to null which is returned to the caller which can then continue its evaluation. If expr doesn’t raise an error, the value returned by expr is returned by try.

try(expr, errexpr) evaluates expr and, if no error is raised, returns the value returned by expr. If an error occurs during evaluation of expr, errexpr is evaluated and its value is returned (which might be an error if the evaluation of errexpr raised one).

Examples

x ≔ 0; try(x ≔ 10 / RandomInt(−5, 6)); x

−5

See also

• assert

• succeeded