I have a model which has a column named code, which is a combination of the model's name column and its ID with leading zeros.
name = 'Rocky'
id = 16
I have an after_create callback which runs and generates the code:
update(code: "#{self.name[0..2].upcase}%.4d" % self.id)
The generated code will be:
"ROC0016"
The code is working.
I found (%.4d" % self.id) from another project, but I don't know how it works.
How does it determine the number of zeros to be preceded based on the passed integer.
You’re using a "format specifier". There are many specifiers, but the one you’re using, "%d", is the decimal specifier:
% starts it. 4 means it should always use at least four numbers, so if the number is only two digits, it gets padded with 0s to fill in the rest of the numbers. The second % means replace 4d with whatever comes after it. So in your case, 4d is getting replaced with "0016".
sprintf has more information about format specifiers.
You can read more about String#% in the documentation also.
After the percentage sign ("%") is a decimal (".") and a number. That number is the number of total digits in the result. If the result is less than this value, additional zeros will be added.
Thus, in this first example, the result is "34" but length was set to "4". The result will have two leading zeros to fill it into four digits.
"This is test string %.4d" % 34
result => "This is test string 0034"
"I want more zeroes in my code %.7d" % 34
result => "I want more zeroes in my code 0000034"
Related
I'm making a list for buying groceries in Google Sheets and have the following value in cell B4.
0.95 - Lemon Juice
2.49 - Pringle Chips
1.29 - Baby Carrots
9.50 - Chicken Kebab
What I'm trying to do is split using the dash character and combine the costs (0.95+2.49+1.29+9.50).
I've tried to use Index(SPLIT(B22,"-"), 7) and SPLIT(B22,"-") but I don't know how to use only numbers from the split string.
Does someone know how to do this? Here's a sample sheet.
Answer
The following formula should produce the result you desire:
=SUM(ARRAYFORMULA(VALUE(REGEXEXTRACT(SPLIT(B4,CHAR(10)),"(.*)-"))))
Explanation
The first thing to do is to split the entry in B4 into its component parts. This is done by using the =SPLIT function, which takes the text in B4 and returns a separate result every time it encounters a specific delimiter. In this case, that is =CHAR(10), the newline character.
Next, all non-number information needs to be removed. This is relatively easy in your sample data because the numbers always appear to the left of a dash. =REGEXEXTRACT uses a regular expression to only return the text to the left of the dash.
Before the numbers can be added together, however, they must be converted to be in a number format. The =VALUE function is used to convert each result from a text string containing a number to an actual number.
All of this is wrapped in an =ARRAYFORMULA so that =VALUE and =REGEXEXTRACT parse each returned value from =SPLIT, rather than just the first.
Finally, all results are added together using =SUM.
Functions used:
=CHAR
=SPLIT
=REGEXEXTRACT
=VALUE
=ARRAYFORMULA
=SUM
Firstly you can add , symbols start and ends of numbers with below code:
REGEXREPLACE(B4,"([0-9\.]+)",",$1,")
Then split it based of , sign.
SPLIT(A8, ",")
Try below formula (see your sheet)-
=SUM(ArrayFormula(--REGEXEXTRACT(SPLIT(B4,CHAR(10)),"-*\d*\.?\d+")))
I'm creating a Lua script which will calculate a temperature value then format this value as a 4 digit hex number which must always be 4 digits. Having the answer as a string is fine.
Previously in C I have been able to use
data_hex=string.format('%h04x', -21)
which would return ffeb
however the 'h' string formatter is not available to me in Lua
dropping the 'h' doesn't cater for negative answers i.e
data_hex=string.format('%04x', -21)
print(data_hex)
which returns ffffffeb
data_hex=string.format('%04x', 21)
print(data_hex)
which returns 0015
Is there a convenient and portable equivalent to the 'h' string formatter?
I suggest you try using a bitwise AND to truncate any leading hex digits for the value being printed.
If you have a variable temp that you are going to print then you would use something like data_hex=string.format("%04x",temp & 0xffff) which would remove the leading hex digits leaving only the least significant 4 hex digits.
I like this approach as there is less string manipulation and it is congruent with the actual data type of a signed 16 bit number. Whether reducing string manipulation is a concern would depend on the rate at which the temperature is polled.
For further information on the format function see The String Library article.
How can I test if a certain character of a string variable is a digit in SPSS (and then apply some operations, depending on the result)?
So let's for example say, I have a variable that reflects the street number. Some street numbers have additional character at the end e.g. "12b". Now let's further assume that I extracted the last character (that could be a digit, or the additional letter) into a string variable. After that I'd like to check if this character is a digit or a letter. How can this be done?
I managed to do this with the MAX function, where "mychar" is the character variable to be checked:
COMPUTE digitcheck = (MAX(mychar,"9")="9").
If the content of "mychar" is a digit [0-9] the result of the MAX function will be "9" otherwise the MAX function will return the letter and the equality test fails.
In this way you can also check if a whole string variable contains a letter or not. It looks pretty ugly though, because you have to compare every single character of your string variable.
compute justdigits = (MAX((CHAR.SUBSTR(mystr,1,1), CHAR.SUBSTR(mystr,2,1), CHAR.SUBSTR(mystr,3,1), ..., CHAR.SUBSTR(mystr,n,1),"9")="9").
If you try to turn a letter into a number then it becomes a missing value. Therefore, to test whether a character is a digit, you can do this:
if not missing(number(YourCharacter,f1)) .....
The same test can determine whether a string has only a number in it or not:
compute OnlyNumber=(not missing(number(YourString,f10))).
Note: using the number command on strings will produce warning messages which you can of course ignore.
The value in variable VAR is -1, and when I am trying to write to a file, it gets displayed as J(character mode), which is equivalent to -1.
The VAR is defined in Cobol program copybook as below:
10 VAR PIC S9(1).
Is there any way, to change the display format from character "J" to -1, in the output file.
The information which I found by googling is below:
Value +0 Character {
Value -0 Character }
Value +1 Character A
To convert the zoned ASCII field which results from an EBCDIC to ASCII character translation to a leading sign numeric field, inspect the last digit in the field. If it's a "{" replace the last digit with a 0 and make the number positive. If it's an "A" replace the last digit with a 1 and make the number positive, if it's a "B" replace the last digit with a 2 and make the number positive, etc., etc. If the last digit is a "}" replace the last digit with a 0 and make the number negative. If it's a "J" replace the last digit with a 1 and make the number negative, if it's a "K" replace the last digit with a 2 and make the number negative, etc., etc. Follow these rules for all possible values. You could do this with a look-up table or with IF or CASE statements. Use whatever method suits you best for the language you are using. In most cases you should put the sign immediately before the first digit in the field. This is called a floating sign, and is what most PC programs expect. For example, if your field is 6 bytes, the value -123 should read " -123" not "- 123".
It might be simpler to move it to an EBCDIC output (display) field so that its just EBCDIC characters, and then convert that to ASCII and write it.
For example
10 VAR PIC S9(1).
10 WS-SEPSIGN PIC S9(1) SIGN IS LEADING SEPARATE.
10 WS-DISP REDEFINES WS-SEPSIGN
PIC XX.
MOVE VAR TO WS-SEPSIGN.
Then convert WS-OUT to ASCII using a standard lookup table and write it to the file.
If you are sending data from an EBCDIC machine to an ASCII machne, or vice versa, by far the best way is to only deal with character data. You can then let the transfer/communication mechanism do the ASCII/EBCDIC translation at record/file level.
Field-level translation is possible, but is much more prone to error (fields must be defined, accurately, for everything) and is slower (many translations versus one).
The SIGN clause is a very good way to do this. There is no need to REDEFINES the field (again you get to issues with field-definitions, two places to change if the size is changed).
There is a similar issue with decimal places where they exist. Where source and data definitions are not the same, an explicit decimal-point has to be provided, or a separate scaling-factor.
Both issues, and the original issue, can also be dealt with by using numeric-edited definitions.
01 transfer-record.
...
05 numeric-edited-VAR1 PIC +9.
...
With positive one, that will contain +1, with negative one, that will contain -1.
Take an amount field:
01 VAR2 PACKED-DECIMAL PIC S9(7)V99.
...
01 transfer-record.
...
05 numeric-edited-VAR2 PIC +9(7).99.
...
For 4567.89, positive, the new field will contain +0004567.79. For the same value, but negative, -0004567.79.
The code on the Source-machine is:
MOVE VAR1 TO numeric-edited-VAR1
MOVE VAR2 TO numeric-edited-VAR2
And on the target (in COBOL)
MOVE numeric-edited-VAR1 TO VAR1
MOVE numeric-edited-VAR2 TO VAR2
The code is the same if you use the SIGN clause for fields without decimal places (or with decimal places if you want the danger of being implicit about it).
Another thing with field-level translation is that Auditors don't/shouldn't like it. "The first thing you do when the data arrives is you change it? Really?" says the Auditor.
So I have entered my second semester of College and they have me doing a course called Advanced COBOL. As one of my assignments I have to my make a program that tests certain things in a file to make sure the input has no errors. I get the general idea but there are just a few things I don't understand and my teacher is one of those people who will give you an assignment and make you figure it out yourself with little or no help. So here is what I need help with.
I have a field that the first 5 columns have to be numbers, the 6th column a capital letter and the last 2 numbers in a range of 01-68 or 78-99.
one of my fields has to be a string of numbers with a dash in it like 00000-000, but some have more than one dash. How can I count the dashes to identify that there is a problem.
Here are a few hints...
Use a hieratical record structure to view the data in different ways. For example:
01 ITEM-REC.
05 ITEM-CODE.
10 ITEM-NUM-CODE PIC 9(3).
10 ITEM-CHAR-CODE PIC A(3).
88 ITEM-TYPE-A VALUE 'AAA' THRU 'AZZ'.
88 ITEM-TYPE-B VALUE 'BAA' THRU 'BZZ'.
05 QUANTITY PIC 9(4).
ITEM-CODE is a 6 character group field, the first part of which is numeric (ITEM-NUM-CODE) and the last part
is alphabetic (ITEM-CHAR-CODE). You can refer to any one of these three variables in your program. When you
refer to ITEM-CODE, or any other group item, COBOL
treats the variable as if it were declared as PIC X. This means you can
MOVE just about anything into it without raising an error. For example:
MOVE 'ABCdef' TO ITEM-CODE
or
MOVE 'ABCdef0005' TO ITEM-REC
Neither one would cause an error even though the elementary data item ITEM-NUM-CODE is definitely not a number.
To verify the validity
of your data after a group move you should validate each elementary data item separately (unless
you know for certain no data type errors could have occurred). There are a variety of ways to do this. For
example if the data item has to be numeric the following would work:
IF ITEM-NUM-CODE IS NUMERIC
CONTINUE
ELSE
DISPLAY 'ITEM-NUM-CODE IS NOT NUMERIC'
PERFORM BIG-BAD-ERROR
END-IF
COBOL provides various class tests which can be applied against a data item. For
example: NUMERIC, ALPHABETIC and ALPHANUMERIC are commonly used.
Another common way to test for ranges of values is by defining various 88 levels - but exercise
caution. In the above
example ITEM-TYPE-A is an 88 level that defines a data range from 'AAA' through 'AZZ' based on
the collating sequence currently in effect. To verify that ITEM-CHAR-CODE contains only alphabetic
characters and the first letter is an 'A' or a 'B', you could do something like:
IF ITEM-CHAR-CODE ALPHABETIC
DISPLAY 'ITEM-CHAR-CODE is alphabetic.'
EVALUATE TRUE
WHEN ITEM-TYPE-A
DISPLAY 'ITEM-CHAR-CODE is in range AAA through AZZ'
WHEN ITEM-TYPE-B
DISPLAY 'ITEM-CHAR-CODE is in range BAA through BZZ'
WHEN OTHER
DISPLAY 'ITEM-CHAR-CODE is in some other range'
END-EVALUATE
ELSE
DISPLAY 'ITEM-CHAR-CODE is not alphabetic'
END-IF
Note the separate test for ALPHABETIC above. Why do that when the 88 level tests
could have done the job? Actually the 88's are not sufficient because they
cover the entire range from AAA through AZZ based on the collating sequence currently
in effect. In
an EBCDIC based environment (a very large number of COBOL shops use EBCDIC) this captures
values such as A}\. the close-brace and backslash characters are non-alpha but
fall into the middle of
the range 'A' through 'Z' (what the #*#! is that all about?). Also note that a value such
as 'aaa' would not satisfy the ITEM-TYPE-A condition because lower case letters fall outside
the defined range. Maybe time to check out an EBCDIC character table.
Finally, you can count the number of occurrences of a character, or string of characters, in
a variable with the INSPECT verb as follows:
INSPECT ITEM-CODE TALLING DASH-COUNT FOR ALL '-'
DASH-COUNT needs to be a numeric item and will contain the number of dash characters in ITEM-CODE. The INSPECT
verb is not so useful if you want to count the number of digits. For this you would need one statement for each digit.
It might be easier to just code a loop something like:
PERFORM VARYING I FROM 1 BY 1
UNTIL I > LENGTH OF ITEM-CODE
EVALUATE ITEM-CODE(I:1)
WHEN '-'
COMPUTE DASH-COUNT = DASH-COUNT + 1
WHEN '0' THRU '9'
COMPUTE DIGIT-COUNT = DIGIT-COUNT + 1
WHEN OTHER
COMPUTE OTHER-COUNT = OTHER-COUNT + 1
END-EVALUATE
END-PERFORM
Now ask yourself why I was comfortable using a zero through 9 range check? Hint: look at the collating sequence.
Hope this helps.