Your example is not a good one in that it is very unlikely that the performance will be signficantly different. In your example readability should trump performance because the performance gain of one vs the other is negligable. The benefits of an array (StringBuffer) are only apparent when you are doing many concatentations. Even then … Read more
concat.js is being included in the concat task’s source files public/js/*.js. You could have a task that removes concat.js (if the file exists) before concatenating again, pass an array to explicitly define which files you want to concatenate and their order, or change the structure of your project. If doing the latter, you could put … Read more
As ghostdog74 said, but this time with headers: with open(“out.csv”, “ab”) as fout: # first file: with open(“sh1.csv”, “rb”) as f: fout.writelines(f) # now the rest: for num in range(2, 201): with open(“sh”+str(num)+”.csv”, “rb”) as f: next(f) # skip the header, portably fout.writelines(f)
As per the C11 standard, chapter ยง5.1.1.2, concatenation of adjacent string literals: Adjacent string literal tokens are concatenated. happens in translation phase. On the other hand: printf(“Hi” (test ? “Bye” : “Goodbye”)); involves the conditional operator, which is evaluated at run-time. So, at compile time, during the translation phase, there are no adjacent string literals … Read more
As other answers have said, the string concatenation operator in Lua is two dots. Your simple example would be written like this: filename = “checkbook” filename = filename .. “.tmp” However, there is a caveat to be aware of. Since strings in Lua are immutable, each concatenation creates a new string object and copies the … Read more
This works for me: =CONCATENATE(“”””,A1,””””) Repeating the quotes escapes them (as it does in Visual Basic, I believe), so “””” reads as: ‘one quote to start a string, one escaped quote (“”), then one quote to finish the string’.
The easiest way would be Section = ‘Sec_’ + Section But for efficiency, see: https://waymoot.org/home/python_string/
The WM_CONCAT function (if included in your database, pre Oracle 11.2) or LISTAGG (starting Oracle 11.2) should do the trick nicely. For example, this gets a comma-delimited list of the table names in your schema: select listagg(table_name, ‘, ‘) within group (order by table_name) from user_tables; or select wm_concat(table_name) from user_tables; More details/options Link to … Read more
The problem is that when you have a macro replacement, the preprocessor will only expand the macros recursively if neither the stringizing operator # nor the token-pasting operator ## are applied to it. So, you have to use some extra layers of indirection, you can use the token-pasting operator with a recursively expanded argument: #define … Read more
The extra work is probably not worth it, unless you really really need efficiency. You probably will have much better efficiency simply by using operator += instead. Now after that disclaimer, I will answer your actual question… The efficiency of the STL string class depends on the implementation of STL you are using. You could … Read more