In String.replace("\c","") what ASCII value is ""? - string

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.

Related

Why the string in unicode form is not equal to its unicode code point value?

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.

How to operate with the first character of a string?

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?

Removing special characters from a string In a Groovy Script

I am looking to remove special characters from a string using groovy, i'm nearly there but it is removing the white spaces that are already in place which I want to keep. I only want to remove the special characters (and not leave a whitespace). I am running the below on a PostCode L&65$$ OBH
def removespecialpostcodce = PostCode.replaceAll("[^a-zA-Z0-9]+","")
log.info removespecialpostcodce
Currently it returns L65OBH but I am looking for it to return L65 OBH
Can anyone help?
Use below code :
PostCode.replaceAll("[^a-zA-Z0-9 ]+","")
instead of
PostCode.replaceAll("[^a-zA-Z0-9]+","")
To remove all special characters in a String you can use the invert regex character:
String str = "..\\.-._./-^+* ".replaceAll("[^A-Za-z0-1]","");
System.out.println("str: <"+str+">");
output:
str: <>
to keep the spaces in the text add a space in the character set
String str = "..\\.-._./-^+* ".replaceAll("[^A-Za-z0-1 ]","");
System.out.println("str: <"+str+">");
output:
str: < >

AS3 - "\u2605" NOT the same as "\\u"+"2605"?

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()

Adding blank spaces into a string in C#

I have this code
String coNum = customerOrderLine.coNum.PadLeft(10 - customerOrderLine.coNum.Length);
I know that customerOrderLine.coNum = "123456" So I should end up with coNum being having 4 empty spaces at the front of it but I end up with it being "123456". How do I fix this? I tried PadRight in case that was the mistake and it also failed to work. I have to have the 4 empty spaces at the beginning to pass it into the API I am working on or it will fail.
PadLeft takes a total length as a parameter, so I think you want
String coNum = customerOrderLine.coNum.PadLeft(10);
This is because you have incorrectly specified the totalWidth parameter of the Pad* method.
From docs:
The number of characters in the resulting string, equal to the number
of original characters plus any additional padding characters.[...] If totalWidth is equal to the length of this instance, the method
returns a new string that is identical to this instance.
PadLeft does not specify a default character to pad with; your second argument should be the character to use for the pad, i.e.:
String coNum = customerOrderLine.coNum.PadLeft(10, ' ');
Edit: Also the first argument should be total desired length, not number of pad characters to add, per #Matthew's answer.

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