extract a letter from a string in Lua - lua

i have the string price that has a value with a number in it. I have code that extracts the number, I need help to figure out how to have another string (pricechar) with only the "k" in it
price="1k"
--pricechar=...
pricenum=string.match(price,"%d+")

You can extract all non-numeric characters, similar to how you do it for numbers:
pricechar = string.match(price,"[^%d]+")

To get both values at the same time:
pricenum, pricechar = string.match(price,"(%d+)(.*)")

Related

extract number with seperated point in a string ruby

How to extract a point separated number format from a string?
for example a string like this
a = 'ProductX credit 1.000'
how to to get only the 1.000 from that string?
Thank you kindly
You can use method split by space in ruby
a = 'ProductX credit 1.000'
a.split(" ").last
Result
"1.000"
Input
a='ProductX credit 1.000'
Code
p a.rpartition(/\s/).last
Output
"1.000"

How to extract double from string in dart?

I have a string containing 3 or 4 double numbers. what's the best way to extract them in an array of numbers?
First you have to find the numerals. You can use a RegExp pattern for that, say:
var doubleRE = RegExp(r"-?(?:\d*\.)?\d+(?:[eE][+-]?\d+)?");
Then you parse the resulting strings with double.parse. Something like:
var numbers = doubleRE.allMatches(input).map((m) => double.parse(m[0])).toList();

Swift: getting character from string (ascii value)

I'm trying to get the character value in ascii and also the character at index.
I have this Objective-C any of you would know the conversion to swift?
po [strToSort characterAtIndex:i] // character x
U+0078 u'x'
po [strToSort UTF8String][i]
x
I'll really appreciate your help.
Updated: you can directly subscript string with an Index
Swift doesn't allow you to subscript Strings with an Integer index. Instead you can construct an index to pass in.
let str = "String with some characters"
let index = str.startIndex.advancedBy(5)
let character = str[index]
print(character) // "g"
For more information on why you can't treat strings as a direct sequence of characters, you can find more info here.
Essentially to be properly unicode compliant, sometimes multiple characters can be combined to create a single character in the final string. This causes issues with naive counting and indexing.
If you want a utf8 representation of the string, String provides a utf8 property as well as a unicodeScalars property for getting the code point for each character.

Converting type string to long

I am trying to convert the type of string to long in the following code:
PaymentReceived = String.Format(new CultureInfo("en-IN", true), "{0:n}", t.PaymentReceived),
Here t.PaymentReceived is of type long, and the PaymentReceived is of type string but I want it to be of type long.
I am using this to convert the PaymentReceived value into comma separated value.
I am trying to do as of my knowledge like
PaymentReceived = Convert.ToInt64( String.Format(new CultureInfo("en-IN", true), "{0:n}", t.PaymentReceived))
But the error is Additional information: Input string was not in a correct format.
So please help me with another solution, thank you.
The formatter n, adds additional non-numeric characters. For en-IN culture, that means a number like 1000 ends up as 1,000.00.
The Convert.ToInt64 method requires that the string be 100% numeric, including no period, which might be fine for Convert.ToDecimal, but a long is not a float. Therefore, emphatically, your string is not formatted correctly, and the error is both obvious and correct. I'm not sure what your ultimate goal here is, but it makes no sense to convert a long to a formatted string and then immediately convert it back to a long, anyways.
Assuming you have only the string and you need to format it as a long, then you need to ensure that it's formatted as a long should be. That requires:
Split on the decimal point and take just the left side:
str = str.Split(new[] { '.' })[0];
Replace any commas with empty strings:
str = str.Replace(",", "");
That assumes you know the format will something like 1,000.00. Otherwise, you may want to use a regex to replace all non-numeric characters with an empty string, instead. However, you still need to split on the decimal. Otherwise, if you just removed all non-numeric characters from something like 1,000.00, then you'd end up with 100000, a number 100 times larger than the actual string number. Also, this is all dependent on the culture. Some cultures use , as the decimal separator and . and delimiter in large numbers. If you need to handle various cultures, you'll need to adjust accordingly.

from list to string and back to list

I have read a multiline file and converted it to a list with the following code:
Lines = string:tokens(erlang:binary_to_list(Binary), "\n"),
I converted it to a string to do some work on it:
Flat = string:join(Lines, "\r\n"),
I finished working on the string and now I need to convert it back to a multiline list, I tried to repeat the first snippet shown above but that never worked, I tried string:join and that didnt work.. how do i convert it back to a list just like it used to be (although now modified)?
Well that depends on the modifications you made on the flattened string.
string:tokens/2 will always explode a string using the separator you provide. So as long as your transformation preserves a specific string as separator between the individual substrings there should be no problem.
However, if you do something more elaborate and destructive in your transformation then the only way is to iterate on the string manually and construct the individual substrings.
Your first snippet above contains a call to erlang:binary_to_list/1 which first converts a binary to a string (list) which you then split with the call to string:tokens/2 which then join together with string:join/2. The result of doing the tokens then join as you have written it seems to be to convert it from a string containing lines separated by \n into one containing lines separated by \r\n. N.B. that this is a flat list of characters.
Is this what you intended?
What you should do now depends on what you mean by "I need to convert it back to a multiline list". Do you mean everything in a single list of characters (string), or in a nested list of lines where each line is a list of characters (string). I.e. if you ended up with
"here is line 1\r\nhere is line 2\r\nhere is line 3\r\n"
this already is a multiline line list, or do you mean
["here is line 1","here is line 2","here is line 3"]
Note that each "string" is itself a list of characters. What do you intend to do with it afterwards?
You have your terms confused. A string in any language is a sequence of integer values corresponding to a human-readable characters. Whether the representation of the value is a binary or a list does not matter, both are technically strings because of the data they contain.
That being said, you converted a binary string to a list string in your first set of instructions. To convert a list into a binary, you can call erlang:list_to_binary/1, or erlang:iolist_to_binary/1 if your list is not flat. For instance:
BinString = <<"this\nis\na\nstring">>.
ListString = "this\nis\na\nstring" = binary_to_list(BinString).
Words = ["this", "is", "a", "string"] = string:tokens(ListString, "\n").
<<"thisisastring">> = iolist_to_binary(Words).
Rejoined = "this\r\nis\r\na\r\nstring" = string:join(Words, "\r\n").
BinAgain = <<"this\r\nis\r\na\r\nstring">> = list_to_binary(Rejoined).
For your reference, the string module always expects a flat list (e.g., "this is a string", but not ["this", "is", "a", "string"]), except for string:join, which takes a list of flat strings.

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