2.5.9 Loops and Control Structures - Wolfram Research

2.5 Evaluation of Expressions 345In this case, overflow is not generated,and the Catch has no effect.In[19]:= Catch[ 2 + g[5] ]Out[19]= 122Functions like Continue[ ] and Break[ ] allow you to “transfer control” to the beginning or endof a loop in a Mathematica program. Sometimes you may instead need to transfer control to a particularelement in a Mathematica procedure. If you give a Label as an element in a procedure, you can useGoto to transfer control to this element.This goes on looping until q exceeds 6.In[20]:= (q = 2 Label[begin] Print[q] q += 325If[q < 6, Goto[begin]])Note that you can use Goto in a particular Mathematica procedure only when the Label it specifiesoccurs as an element of the same Mathematica procedure. In general, use of Goto reduces the degree ofstructure that can readily be perceived in a program, and therefore makes the operation of the programmore difficult to understand.Web sample page from The Mathematica Book, Second Edition, by Stephen Wolfram, published by Addison-Wesley Publishing Company (hardcoverISBN 0-201-51502-4; softcover ISBN 0-201-51507-5). To order Mathematica or this book contact Wolfram Research: info@wolfram.com;http://www.wolfram.com/; 1-800-441-6284.© 1991 Wolfram Research, Inc. Permission is hereby granted for web users to make one paper copy of this page for their personal use. Further reproduction,or any copying of machine-readable files (including this one) to any server computer, is strictly prohibited.