String variable interpolation Java [duplicate]
If you’re using Java 5 or higher, you can use String.format: urlString += String.format(“u1=%s;u2=%s;u3=%s;u4=%s;”, u1, u2, u3, u4); See Formatter for details.
string-interpolation
Python: format string with custom delimiters [duplicate]
I don’t think it is possible to use alternative delimiters. You need to use double-curly braces {{ }} for curly braces that you don’t want to be replaced by format(): inp = “”” DATABASE = {{ ‘name’: ‘{DB_NAME}’ }}””” dictionary = {‘DB_NAME’: ‘abc’} output = inp.format(**dictionary) print(output) Output DATABASE = { ‘name’: ‘abc’ }
Escape a dollar sign in string interpolation
Just double it scala> val name = “foo” name: String = foo scala> s”my.package.$name$$” res0: String = my.package.foo$
Using C# 6 features with CodeDomProvider (Roslyn)
Update: March 2018 Word of caution, NuGet version 1.0.6 … 1.0.8 will not copy the /roslyn folder to the build output directory on non-web projects. Best stick with 1.0.5 https://github.com/aspnet/RoslynCodeDomProvider/issues/38 Run-time compilation using C#6 features requires a new compiler, as @thomas-levesque mentioned. This compiler can be installed by using the nuget package Microsoft.CodeDom.Providers.DotNetCompilerPlatform. For desktop … Read more
String Interpolation vs String.Format
Noticable is relative. However: string interpolation is turned into string.Format() at compile-time so they should end up with the same result. There are subtle differences though: as we can tell from this question, string concatenation in the format specifier results in an additional string.Concat() call.
Transform string to f-string
An f-string is syntax, not an object type. You can’t convert an arbitrary string to that syntax, the syntax creates a string object, not the other way around. I’m assuming you want to use user_input as a template, so just use the str.format() method on the user_input object: variable = 42 user_input = “The answer … Read more
PHP variable interpolation vs concatenation [duplicate]
Whatever works best for you works… But if you want to go for speed use this: echo ‘Welcome ‘, $name, ‘!’; The single quotes tell PHP that no interpretation is needed, and the comma tells PHP to just echo the string, no concatenation needed.
bash variable interpolation separate variables by a hyphen or underscore
By telling bash where the variable name ends. “${filename}_$yesterday.CSV”
How to substitute shell variables in complex text files
Looking, it turns out on my system there is an envsubst command which is part of the gettext-base package. So, this makes it easy: envsubst < “source.txt” > “destination.txt” Note if you want to use the same file for both, you’ll have to use something like moreutil’s sponge, as suggested by Johnny Utahh: envsubst < … Read more
How do I convert a string into an f-string?
f-strings are code. Not just in the safe, “of course a string literal is code” way, but in the dangerous, arbitrary-code-execution way. This is a valid f-string: f”{__import__(‘os’).system(‘install ransomware or something’)}” and it will execute arbitrary shell commands when evaluated. You’re asking how to take a string loaded from a text file and evaluate it … Read more