How to Eliminate Blanks Between Words in a String?
EXAMINE
By Dieter W. Storr
Last update: 25 July 2007
Question:
How can you remove any number of blanks between words in a string.
Example
Input
A B C D E
Output
A B C D E
Solution 1 (good) - sent by Mark Keating:
EXAMINE #A20 FOR FULL H'4040' REPLACE WITH H'40FF'
EXAMINE #A20 FOR FULL H'FF40' DELETE
EXAMINE #A20 FOR H'FF' DELETE
Solution 2 (better) - sent by Jim Wisdom:
SEPARATE #STRING INTO #WORDS (*) WITH DELIMITER ' '
COMPRESS #WORDS (*) INTO #STRING
Solution 3 (best) - sent by Helmut Spichtinger:
EXAMINE #STRING FOR FULL H'40' WITH DELIMITER H'40' DELETE
EXAMINE #STRING FOR FULL H'4040' REPLACE H'40'
Jim Wisdom wrote after he compared solution 2 and 3:
"Comparison complete. Helmut’s suggestion of the 2 EXAMINE statements beat the pants off my SEPARATE/COMPRESS idea which also requires extra storage.
I know what I’m going to do from now on!"
See also: Do not EXAMINE arrays.
Source code and tests from Dieter Storr
0010 DEFINE DATA LOCAL
0020 1 #STRING (A50)
0030 1 #WORDS (A1/1:50)
0040 1 #I (P10)
0050 END-DEFINE
0060 *
0070 SETA. SETTIME
0080 FOR #I = 1 TO 30000
0090 #STRING := 'A B C D E F '
0100 EXAMINE #STRING FOR FULL H'4040' REPLACE WITH H'40FF'
0110 EXAMINE #STRING FOR FULL H'FF40' DELETE
0120 EXAMINE #STRING FOR H'FF' DELETE
0130 END-FOR
0140 WRITE 'Solution 1:' #STRING *TIMD(SETA.)
0150 *
0160 #STRING := 'A B C D E F '
0170 SETB. SETTIME
0180 FOR #I = 1 TO 30000
0190 SEPARATE #STRING INTO #WORDS (*) WITH DELIMITER ' '
0200 COMPRESS #WORDS (*) INTO #STRING
0210 END-FOR
0220 WRITE 'Solution 2:' #STRING *TIMD(SETB.)
0230 *
0240 SETC. SETTIME
0250 FOR #I = 1 TO 30000
0260 #STRING := 'A B C D E F '
0270 EXAMINE #STRING FOR FULL H'40' WITH DELIMITER H'40' DELETE
0280 EXAMINE #STRING FOR FULL H'4040' REPLACE H'40'
0290 END-FOR
0300 WRITE 'Solution 3:' #STRING *TIMD(SETC.)
0310 END
Executed stowed program -- online:
IBM z/OS 1.04.00, IBM 2066-0X2, 160 mips -- NAT413, COM631
Page 1 07-07-20 15:45:53
Solution 1: A B C D E F 13
Solution 2: A B C D E F 23
Solution 3: A B C D E F 13
Page 1 07-07-20 15:47:00
Solution 1: A B C D E F 14
Solution 2: A B C D E F 24
Solution 3: A B C D E F 14
Page 1 07-07-20 15:48:50
Solution 1: A B C D E F 13
Solution 2: A B C D E F 22
Solution 3: A B C D E F 14
Page 1 07-07-20 15:54:09
Solution 1: A B C D E F 13
Solution 2: A B C D E F 23
Solution 3: A B C D E F 18
Page 1 07-07-24 15:03:44
Solution 1: A B C D E F 170
Solution 2: A B C D E F 259
Solution 3: A B C D E F 335
Page 1 07-07-24 15:08:11
Solution 1: A B C D E F 54
Solution 2: A B C D E F 79
Solution 3: A B C D E F 54
Executed stowed program -- batch
IBM z/OS 1.04.00, IBM 2066-0X2, 160 mips -- NAT413
Page 1 07-07-24 15:16:03
Solution 1: A B C D E F 95
Solution 2: A B C D E F 82
Solution 3: A B C D E F 33
Page 1 07-07-24 15:27:31
Solution 1: A B C D E F 39
Solution 2: A B C D E F 146
Solution 3: A B C D E F 57
Page 1 07-07-25 11:12:48
Solution 1: A B C D E F 12
Solution 2: A B C D E F 21
Solution 3: A B C D E F 15
Additional info from Steve Robinson:
I ran my comparison on both the PC and the mainframe.
I did have a slightly different string, here it is:
1 #STRING (A30) INIT <'ABC D E F G H'>
Here are the PC results (100,000 iterations)
PAGE # 1 DATE: Jul 21, 2007
PROGRAM: BLANKS01 LIBRARY: INSIDE
DUMMY FOR LOOP TIME 7 70
SEPARATE 78 768
EXAMINE 3 TIME 24 230
EXAMINE 2 TIME 20 197
and here are the mainframe results (also 100,000 iterations)
MORE
PAGE # 1 DATE: 07-07-21
PROGRAM: BLANKS01 LIBRARY: XSTRO
DUMMY FOR LOOP TIME 0 7
SEPARATE 16 134
EXAMINE 3 TIME 10 87
EXAMINE 2 TIME 11 91
Each of the above is representative of several runs on each platform. The two EXAMINE comes out best on the PC, while the three EXAMINEs prevails on the mainframe.
Interestingly enough, on the mainframe the SEPARATE is "not that bad"; only half again the two EXAMINEs. By contrast, on the PC the SEPARATE is triple the EXAMINEs.
Also of note; for shops considering such a transition, the mainframe numbers (same number of iterations) are only half (or a little less) the PC numbers. And my desktop PC is still a 600 MhZ system; a far cry from the 3 Gig screamers that are available for practically nothing these days.
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