# mass confusion on MASK **URL:** \ **Category:** Forum\ **Tags:** Adabas-Natural, Natural, Natural-News-and-General-Topics\ **Created:** [February 14, 2007, 6:22am UTC](https://techcommunity.softwareag.com/t/mass-confusion-on-mask/61948 "2007-02-14T06:22:48Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Jennifer](https://avatars.discourse-cdn.com/v4/letter/j/46a35a/32.png) [@Jennifer](https://techcommunity.softwareag.com/u/Jennifer)\ **Post date:** [February 14, 2007, 6:22am UTC](https://techcommunity.softwareag.com/t/mass-confusion-on-mask/61948/1 "2007-02-14T06:22:48Z")
The help for MASK says that for ‘c’, then one or more positions are checked for c. But is c strictly alpha? What if I say: if blah = MASK(‘99’)? Am I asking it to search for 99 in the first two positions or anywhere in blah? ---
**Author:** ![Ralph\_Zbrog](https://sea1.discourse-cdn.com/techcommunity/user_avatar/techcommunity.softwareag.com/ralph_zbrog/32/78_2.png) [@Ralph\_Zbrog](https://techcommunity.softwareag.com/u/Ralph_Zbrog)\ **Post date:** [February 14, 2007, 7:03am UTC](https://techcommunity.softwareag.com/t/mass-confusion-on-mask/61948/2 "2007-02-14T07:03:36Z")
MASK is positional. To look for a string within a variable, use SCAN. ```auto IF #VAR = SCAN '99' /* Does 99 exist within #VAR? ``` ---
**Author:** ![Wilfried\_B](https://sea1.discourse-cdn.com/techcommunity/user_avatar/techcommunity.softwareag.com/wilfried_b/32/83_2.png) [@Wilfried\_B](https://techcommunity.softwareag.com/u/Wilfried_B)\ **Post date:** [February 14, 2007, 1:56pm UTC](https://techcommunity.softwareag.com/t/mass-confusion-on-mask/61948/3 "2007-02-14T13:56:21Z")
> [@Ralph Zbrog](#): > > MASK is positional. No, that’s not true. MASK can be positional and not positional, too. To look for ‘99’ in a string, you can use mask, too. And you can use it more efficient than SCAN, like in: ```auto IF #VAR = MASK(*'99') /* Does 99 exist within #VAR? IF #VAR = MASK('99') /* Does #VAR bgin with '99'? IF #VAR = MASK(*'99'/) /* Does #VAR end with '99'? ``` MASK indeed is nearly as powerful as regular expressions, but not that complicated (in my opinion). ---
**Author:** ![Matthias1](https://avatars.discourse-cdn.com/v4/letter/m/9fc348/32.png) [@Matthias1](https://techcommunity.softwareag.com/u/Matthias1)\ **Post date:** [February 14, 2007, 3:47pm UTC](https://techcommunity.softwareag.com/t/mass-confusion-on-mask/61948/4 "2007-02-14T15:47:52Z")
[quote="Wilfried B ---
**Author:** ![Steve\_Robinson](https://sea1.discourse-cdn.com/techcommunity/user_avatar/techcommunity.softwareag.com/steve_robinson/32/107_2.png) [@Steve\_Robinson](https://techcommunity.softwareag.com/u/Steve_Robinson)\ **Post date:** [February 14, 2007, 5:57pm UTC](https://techcommunity.softwareag.com/t/mass-confusion-on-mask/61948/5 "2007-02-14T17:57:24Z")
No argument, the wild card additions to MASK give it a lot more capability than SCAN. However, in terms of performance, for the functionality that SCAN was designed for, SCAN is far more efficient than MASK. For example; DEFINE DATA LOCAL 1 #LOOP (P9) 1 #STRING (A20) 1 #CPU-TIME (P9) 1 #CPU-START (P9) END-DEFINE \* INCLUDE AATITLER INCLUDE AASETC \* MOVE _CPU-TIME TO #CPU-START SETA. SETTIME FOR #LOOP = 1 TO 500000 IF #STRING = MASK (_‘X’) IGNORE END-IF END-FOR COMPUTE #CPU-TIME = \*CPU-TIME - #CPU-START WRITE 5T ‘MASK TIME’ \*TIMD (SETA.) 5X #CPU-TIME \* MOVE \*CPU-TIME TO #CPU-START SETB. SETTIME FOR #LOOP = 1 TO 500000 IF #STRING = SCAN (‘X’) IGNORE END-IF END-FOR COMPUTE #CPU-TIME = \*CPU-TIME - #CPU-START WRITE 5T ‘SCAN TIME’ \*TIMD (SETB.) 5X #CPU-TIME \* END PAGE # 1 DATE: Feb 14, 2007 PROGRAM: SCAN01 LIBRARY: SYSTEM ``` MASK TIME 49 489 SCAN TIME 39 388 ``` SCAN is about 20 % faster and uses 25 % less CPU time. If there was an X in the first position of #STRING, the output is: ``` PAGE # 1 DATE: Feb 14, 2007 PROGRAM: SCAN03 LIBRARY: SYSTEM MASK TIME 36 355 SCAN TIME 35 345 ``` The times above are on my PC; will run mainframe times later today (snowing, hailing and raining outside, so will stay in and play on the computer). steve ---
**Author:** ![Steve\_Robinson](https://sea1.discourse-cdn.com/techcommunity/user_avatar/techcommunity.softwareag.com/steve_robinson/32/107_2.png) [@Steve\_Robinson](https://techcommunity.softwareag.com/u/Steve_Robinson)\ **Post date:** [February 14, 2007, 6:18pm UTC](https://techcommunity.softwareag.com/t/mass-confusion-on-mask/61948/6 "2007-02-14T18:18:46Z")
Okay, it’s later. Mainframe numbers are very interesting. First, here are the numbers with no X MASK TIME 19 112 SCAN TIME 9 61 The SCAN is twice as fast as the MASK. With an X in the first position, the numbers are MASK TIME 9 61 SCAN TIME 9 61 So, if the functionality you are looking for requires “searching” for a text string anywhere in an alpha variable, use SCAN, not MASK. steve ---
**Author:** ![Steve\_Robinson](https://sea1.discourse-cdn.com/techcommunity/user_avatar/techcommunity.softwareag.com/steve_robinson/32/107_2.png) [@Steve\_Robinson](https://techcommunity.softwareag.com/u/Steve_Robinson)\ **Post date:** [February 14, 2007, 6:38pm UTC](https://techcommunity.softwareag.com/t/mass-confusion-on-mask/61948/7 "2007-02-14T18:38:47Z")
Getting back to the original question: IF #STRING = MASK(‘AB’) will look for AB in positions 1 and 2 IF #STRING = MASK(??‘AB’) will look for AB in positions 3 and 4 ? . \_ can all be used to indicate "skip a single position - % are the “wildcard” (any number of characters) characters On the PC (mainframe results later) MASK (??‘XX’) is slightly faster (2%) than SCAN, however CPU time is 10% faster than SCAN. steve ---
**Author:** ![Matthias1](https://avatars.discourse-cdn.com/v4/letter/m/9fc348/32.png) [@Matthias1](https://techcommunity.softwareag.com/u/Matthias1)\ **Post date:** [February 14, 2007, 9:08pm UTC](https://techcommunity.softwareag.com/t/mass-confusion-on-mask/61948/8 "2007-02-14T21:08:49Z")
> [@Steve Robinson](#): > > However, in terms of performance, for the functionality that SCAN was designed for, SCAN is far more efficient than MASK. Your test on Solaris: ```auto MASK TIME 56 562 SCAN TIME 47 468 ``` But you can make it much more faster if you use an I4-field as a loop counter… 😉 ```auto MASK TIME 29 282 SCAN TIME 19 195 ``` Anyway: SCAN is slightly faster ---
**Author:** ![system](https://global.discourse-cdn.com/techcommunity/original/3X/c/d/cd19967bb605d28a72d77eb83a1cae22f3df2eb8.svg) [@system](https://techcommunity.softwareag.com/u/system)\ **Post date:** [April 2, 2021, 2:41pm UTC](https://techcommunity.softwareag.com/t/mass-confusion-on-mask/61948/9 "2021-04-02T14:41:03Z")