• ← Break
• → CheckAbort

Catch

WMA link

Catch[expr]

returns the argument of the first Throw generated in the evaluation of
expr.

Catch[expr, form]

returns value from the first Throw[value, tag] for which form matches
tag.

Catch[expr, form, f]

returns f[value, tag].

Exit to the enclosing Catch as soon as Throw is evaluated:

• • Catch[r; s; Throw[t]; u; v]

Define a function that can “throw an exception”:

• • f[x_] := If[x > 12, Throw[overflow], x!]

The result of Catch is just what is thrown by Throw:

• • Catch[f[1] + f[15]]

• • Catch[f[1] + f[4]]