(in swift language) For example " A + D " I want the string A to stay all the time but the value of D changes depending on let's say Hp, so when Hp is fd the string will be "A + fd" and etc
I mean like( "A + %s" % Hp ) for the string in python. Such as here: What does %s mean in Python?
If you are talking about %s, then it's a c-style formatting key, which awaits string variable or value in the list of arguments. In Swift, you compose strings using "\(variable)" syntax, which is called String interpolation, as explained in the documentation:
String Interpolation
String interpolation is a way to construct a new String value from a
mix of constants, variables, literals, and expressions by including
their values inside a string literal. You can use string interpolation
in both single-line and multiline string literals. Each item that you
insert into the string literal is wrapped in a pair of parentheses,
prefixed by a backslash ():
Source: official documentation
Example:
var myVar = "World"
var string = "Hello \(myVar)"
With non-strings:
let multiplier = 3
let message = "\(multiplier) times 2.5 is \(Double(multiplier) * 2.5)"
// Output: message is "3 times 2.5 is 7.5"
Related
I have the following string:
{\"Id\":\"135\",\"Type\":0}
The number in the Id field will vary, but will always be an integer with no comma separator. I'm not sure how to get just that value from that string given that it's string data type and not real "XML". I was toying with the replace() function, but the special characters are making it more complex than it seems it needs to be.
is there a way to convert that to XML or something that I can reference the Id value directly?
Maybe use a regular expression, e.g.
import re
txt = "{\"Id\":\"135\",\"Type\":0}"
x = re.search('"Id":"([0-9]+)"', txt)
if x:
print(x.group(1))
gives
135
It is assumed here that the ids are numeric and consist of at least one digit.
Non-regex answer as you asked
\" is an escape sequence in python.
So if {\"Id\":\"135\",\"Type\":0} is a raw string and if you put it into a python variable like
a = '{\"Id\":\"135\",\"Type\":0}'
gives
>>> a
'{"Id":"135","Type":0}'
OR
If the above string is python string which has \" which is already escaped, then do a.replace("\\","") which will give you the string without \.
Now just load this string into a dict and access element Id like below.
import json
d = json.loads(a)
d['Id']
Output :
135
I am using Swift 4.2. I am getting extraneous characters when formatting one string (s1) from another string(s0) using the %# format code.
I have searched extensively for details of string formatting but have come up with only partial answers including the code in the second line below. I need to be able to format s1 so that I can customize output from a Swift process. I ask this because I have not found an answer while searching for ways to format a string from a string.
I tried the following three statements:
let s0:[String] = ["abcdef"]
let s1:[String] = [String(format:"%#",s0)]
print(s1)
...
The output is shown below. It may not be clear, here, but there are four leading spaces to the left of the abcdef string.
["(\n abcdef\n)"]
How can I format s1 so it does not include the brackets, the \n escape characters, and the leading spaces?
The issue here is you are using an array but a string in s0.
so the following index will help you.
let s0:[String] = ["abcdef"]
let s1:[String] = [String(format:" %#",s0[0])]
I am getting extraneous characters when formatting one string (s1) from another string (s0) ...
The s0 is not a string. It is an array of strings (i.e. the square brackets of [String] indicate an array and is the same as saying Array<String>). And your s1 is also array, but one that that has one element, whose value is the string representation of the entire s0 array of strings. That’s obviously not what you intended.
How can I format s1 so it does not include the brackets, the \n escape characters, and the leading spaces?
You’re getting those brackets because s1 is an array. You’re getting the string with the \n and spaces because its first value is the string representation of yet another array, s0.
So, if you’re just trying to format a string, s0, you can do:
let s0: String = "abcdef"
let s1: String = String(format: "It is ‘%#’", s0)
Or, if you really want an array of strings, you can call String(format:) for each using the map function:
let s0: [String] = ["abcdef", "ghijkl"]
let s1: [String] = s0.map { String(format: "It is ‘%#’", $0) }
By the way, in the examples above, I didn’t use a string format of just %#, because that doesn’t accomplish anything at all, so I assumed you were formatting the string for a reason.
FWIW, we generally don’t use String(format:) very often. Usually we do “string interpolation”, with \( and ):
let s0: String = "abcdef"
let s1: String = "It is ‘\(s0)’"
Get rid of all the unneccessary arrays and let the compiler figure out the types:
let s0 = "abcdef" // a string
let s1 = String(format:"- %# -",s0) // another string
print(s1) // prints "- abcdef -"
I have a character vector like so:
string = 'a(0:2), b(3), c(rand(4, 5)*0.1)';
I'd like to use this char array as input arguments to a function. The arguments would then be:
a(0:2)
b(3)
c(rand(4, 5)*0.1)
How can I parse the string into those input arguments?
At first glance, one could split the string with the ', ' separator, but it would fail for the third argument obviously.
A simple solution is using split as following:
expressions = split(string, "), ");
Then add ")" at the end of each string in expressions.
A literal is the source code representation of a value of a type, such as a number or string
There are 3 kinds of literals in Swift: Integer Literals, Floating-Point Literals and String Literals (please correct me if I'm wrong), Is that means (My Guess) any elements which not belong to a type of Integer, Floating or String is not considered as a literal, and will trigger an error when used as literals
According to what I guess I've tried this let aEmoji = 😀
Question1: Is my guess accurate? If not, I appreciate you could correct me.
Question2: Is there anything else shouldn't use as a literal? (would be nice you could give me some example)
Thanks
A string literal is wrapped in double quotes
let aEmoji = "😀"
From the documentation:
A string literal is a fixed sequence of textual characters
surrounded by a pair of double quotes ("").
Yes, anything that isn't an integer literal (1), floating-point literal (1.0) or String literal ("foo"), Array literal ([foo]), Dictionary literal ([foo : bar]), bool literal (true/false) isn't a literal and would cause an error.
Anything that isn't one of the literals above isn't a literal, and could cause an error (if it's an invalid syntax).
You can make put an emoji in a string literal, however: let aEmoji = "😀"
You can include emojis in a literal String or Character expression by setting it off with double quotes.
The type inferrer will default the expression to a String literal, unless the Character type is specified.
let unicornString = "🦄"
let unicornChar : Character = "🦄"
Else the compiler will treat the emoji (or any unicode character sequence) as an identifier (because emoji can be variable names and such).
The following would be valid:
let 🔑 = "myPassword"
user.authenticateWithPassword(🔑)
I need code for removing all unicode characters in a vb6 string.
If this is UTF-16 text (as normal VB6 String values all are) and you can ignore the issue of surrogate pairs, then this is fairly quick and reasonably concise:
Private Sub DeleteNonAscii(ByRef Text As String)
Dim I As Long
Dim J As Long
Dim Char As String
I = 1
For J = 1 To Len(Text)
Char = Mid$(Text, J, 1)
If (AscW(Char) And &HFFFF&) <= &H7F& Then
Mid$(Text, I, 1) = Char
I = I + 1
End If
Next
Text = Left$(Text, I - 1)
End Sub
This has the workaround for the unfortunate choice VB6 had to make in returning a signed 16-bit integer from the AscW() function. It should have been a Long for symmatry with ChrW$() but it is what it is.
It should beat the pants off any regular expression library in clarity, maintainability, and performance. If better performance is required for truly massive amounts of text then SAFEARRAY or CopyMemory stunts could be used.
Public Shared Function StripUnicodeCharactersFromString(ByVal inputValue As String) As String
Return Regex.Replace(inputValue, "[^\u0000-\u007F]", String.Empty)
End Function
Vb6 - not sure will
sRTF = "\u" & CStr(AscW(char))
work? - You could do this for all char values above 127
StrConv is the command for converting strings.
StrConv Function
Returns a Variant (String) converted as specified.
Syntax
StrConv(string, conversion, LCID)
The StrConv function syntax has these named arguments:
Part Description
string Required. String expression to be converted.
conversion Required. Integer. The sum of values specifying the type of conversion to perform. `128` is Unicode to local code page (or whatever the optional LCID is)
LCID Optional. The LocaleID, if different than the system LocaleID. (The system LocaleID is the default.)