I had a question, if I have an undefined string of characters, but I only want to send to a record the first character of that string, how can I do it?
Related
We can get the string 你's unicode code point value:
u'你'.encode('unicode-escape')
b'\\u4f60'
Why the string in unicode form is not equal to its unicode code point value?
u'你' == u'\x4f\x60'
False
u'你' == u'\\u4f60'
False
It is, but your comparison strings are not correct to compare. The first one is two separate characters of a single byte, and the second one has the backslash escaped, meaning that it is the literal 6 characters \u4f60.
u'你' == u"\u4f60"
True
The encoded byte string has the two backslashes since the encoding escapes it, making it not equivalent even if turned back into a string unless you decode it with unicode-escape as well.
Side note, the u is default in python 3.
Basically, I have a string in Lua, which is a user output, but I want to trim the first character cause I don't really need it. How can I do that?
You cannot delete the first character of a string.
But you can copy a substring that starts from the second character using string.sub
string.sub(s, i [,j])
Returns the substring of s that starts at i and continues until j; i
and j can be negative. If j is absent, then it is assumed to be equal
to -1 (which is the same as the string length)....
So str = str:sub(2) will give you the substring of str that starts at character 2 which is what you want.
In Swift I can create a String variable such as this:
let s = "Hello\nMy name is Jack!"
And if I use s, the output will be:
Hello
My name is Jack!
(because the \n is a linefeed)
But what if I want to programmatically obtain the raw characters in the s variable? As in if I want to actually do something like:
let sRaw = s.raw
I made the .raw up, but something like this. So that the literal value of sRaw would be:
Hello\nMy name is Jack!
and it would literally print the string, complete with literal "\n"
Thank you!
The newline is the "raw character" contained in the string.
How exactly you formed the string (in this case from a string literal with an escape sequence in source code) is not retained (it is only available in the source code, but not preserved in the resulting program). It would look exactly the same if you read it from a file, a database, the concatenation of multiple literals, a multi-line literal, a numeric escape sequence, etc.
If you want to print newline as \n you have to convert it back (by doing text replacement) -- but again, you don't know if the string was really created from such a literal.
You can do this with escaped characters such as \n:
let secondaryString = "really"
let s = "Hello\nMy name is \(secondaryString) Jack!"
let find = Character("\n")
let r = String(s.characters.split(find).joinWithSeparator(["\\","n"]))
print(r) // -> "Hello\nMy name is really Jack!"
However, once the string s is generated the \(secondaryString) has already been interpolated to "really" and there is no trace of it other than the replaced word. I suppose if you already know the interpolated string you could search for it and replace it with "\\(secondaryString)" to get the result you want. Otherwise it's gone.
Trying to make a textfield where people write the unicode without the backslash. I want to add the backslash after they typed it. So the user types u2605 and the code converts it to "\u2605", i then convert this to a unicode character and insert it in textflow.
My code:
this works:
span.text = publicFunctions.htmlUnescape(he.encode("\u2605"))
this doesn't work:
span.text = publicFunctions.htmlUnescape(he.encode("\\u"+"2605"))
how to make a string that acts as a unicode string?
Tried all sorts of things, escape(unescape()), convert to number, "\u", "\u" ... nothing helps.
trace("\u2605" == "\u"+"2605") ... will return false. So will
trace("\u2605" == "\u"+"2605")
"\u2605" is a string with a single character, the character with the code point 2605, while "\\u" + "2605" is a string with 6 characters (the backslash, the u and the four digit number).
If you want to construct a unicode character from just the four digits, you should be able to use String.fromCharCode. The thing is just that the escape sequence uses a hexadecimal number, while the method obviously takes a decimal number. So if the user enters a hexadecimal string, you will have to convert that first:
trace(String.fromCharCode(parseInt('2605', 16)) == '\u2605'));
That's an interesting issue! I don't think you can concatenate a string literal and achieve what you're trying to do. The relevant character escaping happens when the string literal is originally formed, which means that you need the whole sequence together in the first place.
But you should be able to take the user-supplied number and dynamically generate a Unicode string with String.fromCharCode(...).
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/String.html#fromCharCode()
im just writing my own replace method for any weird characters and i used the ASCI value 0, null to replace unwanted characters, i was hoping for them to be 'deleted', but this doesnt work. A gap just appears in the string.
What exactly does String.Replace() do when removing a character for ""? Does it shift them all down and then 'delete' the final character or something?
Strings are immutable - you cannot change a string. You can only create a new string with the characters removed. If you replace a string with the empty string, you simply create a new string that does not contain the matched characters.