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1. • Locked into a program at compile time

     • Static libraries (.lib), while reusable in multiple programs, are locked into a program at compile time. Dynamic (.dll), or shared libraries, on the other hand, exist as separate files outside of the executable file.
     blogs.embarcadero.com › create-and-use-static-library-lib-and-dynamic-dlls-in-c-builder

     Create and use Static Library (.Lib) and Dynamic DLLs in C++ ...

2. Top results related to why is a lib file a static file?

   • Why is a static library's header file not found for archiving?

     Top Answer

     Answered May 23, 2017 · 9 votes

     With the help of another SO questions(https://stackoverflow.com/a/10159481/143225) I was able to get the header file to include.

     Apparently, the archive build process is somehow different than the debug build process. By adding "$(BUILD_ROOT)/../IntermediateBuildFilesPath/UninstalledProducts" to the "User Header Search Paths" build setting it built successfully.

     I'd still like to understand why this isn't working as I expect it. I have a hunch that the project is built to auto include the header files for debug and release builds, but somehow not for archive builds. This is odd because I thought archive builds inherit from either debug or release settings from Xcode's scheme settings.

     Any additional info is welcome.

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     1/5

   • Why is a compiled java bytecode file called a class file?

     Top Answer

     Answered May 12, 2014 · 12 votes

     It is .class because that is what the designers of Java decided on.

     And it is pretty intuitive: a .class file contains the bytecode of a single class. So a single source .java file may result in multiple .class files, even anonymous classes get their own .class files.

     See The class File Format in the JVM specification.

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     2/5

   • Why is a PPM6 file smaller than a PPM3 file?

     Top Answer

     Answered Nov 05, 2012 · 2 votes

     Don't confuse your source data with what actually gets written to a file.

     PPM3 is not represented by 3 bytes per pixel. Well, not in the stored form. You store them as text files. 3 digits (255 for example) stored as text is 3 bytes (a byte per character). Not 1. And I'm not even regarding the white space there.

     PPM6 is stored as binary with indeed 3 bytes per pixel. It will therefore always be smaller.

     Check all answers on Stack Overflow

     3/5

   • Why is there a difference between a .cpp file and a .h file?

     Top Answer

     Answered Jul 18, 2017 · 2 votes

     There are two things going on here.

     When you include a file, the included file is pasted into the including file before the compiler begins compiling. This means there is a complete copy of file.cpp in main.cpp that will be compiled.

     Next, Visual Studio wants to compile cpp files. It sees file.cpp is part of the project, compiles it, and links it with the compiled output of main.cpp to make an executable program.

     The linker now has to deal with two files (probably link.obj and main.obj) that have their own int i. The linker gives up and prints out a multiple definition error message. It doesn't even try to figure out which one is correct because only the intentions of the programmer makes one more correct than the other. You will have to wait for telepathic compiler support in a future C++ standard to sort that mess out. Until then don't do it.

     Note what I wrote earlier about the included file being copied into the including. This means even with int i being defined in file.h you aren't out of trouble.

     If main.cpp and future.cpp both include file.h, you once again have two files with int i. Include guards will not help here because they only stop a header from being duplicated within one compiled file (a translation unit).

     The solution to this is don't define identifiers in headers unless you take steps to make them unique or tell the compiler that it's OK that they aren't. Strongly prefer not defining the identifier to the alternatives.

     For an identifier that is a variable use the extern

     keyword to inform the compiler that i, or any other variable exists, but will be allocated elsewhere. You are then required to define the variable in exactly one elsewhere. eg:

     file.h

     extern int i;-

     file.cpp

     int i = 0;-

     Now main.cpp or any other file can include file.h and use i. All of them are using the same i, so be careful with it. Be very, very careful. There is very often a better way to share a variable across multiple translation units, so spend the time looking for a different solution. You will most likely thank yourself when debugging time comes.

     An alternative is to define the variable as static

     file.h

     static int i;-

     When using static every file that includes file .h has it's own i that is only visible within the including file. The linker is no longer involved. This is also almost always a bad idea. If you have variables that must be defined to support a header file, odds are good what the header really needs is a class.

     For an identifier that is a function, use the inline

     keyword.

     Check all answers on Stack Overflow

     4/5

   • Why is a .wav file created from a .mp3 file much larger in size?

     Top Answer

     Answered Apr 12, 2017 · 4 votes

     The way the two store audio is night and day different. Simply put, a WAV file (which is PCM audio) is storing much more data than the MP3 file is.

     PCM audio quantifies the pressure at each sample. There are many samples taken. CD-quality audio uses 44,100 samples per second, per channel. The red lines here are samples:

     Graph from: http://en.wikipedia.org/wiki/Sampling_rate

     MPEG-1 Layer 3 (and many other lossy audio compression codecs) use a different method for encoding audio. Rather than measuring pressure over time, they measure frequency components over a time. MP3 encoders determine which frequencies are present in a signal for a short period of time, called a frame. A frame may be 576 samples or so long. For those samples, they playback a set of frequencies.

     Now, all of this is overly simplified. MP3 has a lot of nice tricks to filter out frequencies that will be masked by others, and some nice smoothing of the playback to make it sound close to the original.

     You might find my answer here a bit more in depth: https://video.stackexchange.com/a/635/129

     Check all answers on Stack Overflow

     5/5

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3. stackoverflow.com › questions › 913691static libraries - DLL and LIB files - what and why? - Stack ...

   stackoverflow.com › questions › 913691

   • Cached

   May 27, 2009 · There are static libraries (LIB) and dynamic libraries (DLL) - but note that .LIB files can be either static libraries (containing object files) or import libraries (containing symbols to allow the linker to link to a DLL).

   • Another aspect is security (obfuscation). Once a piece of code is extracted from the main application and put in a "separated" Dynamic-Link Library...
   • One important reason for creating a DLL/LIB rather than just compiling the code into an executable is reuse and relocation. The average Java or .NE...
   • A DLL is a library of functions that are shared among other executable programs. Just look in your windows/system32 directory and you will find doz...
   • One other difference lies in the performance. As the DLL is loaded at runtime by the .exe(s), the .exe(s) and the DLL work with shared memory conc...

4. People also ask

   Why is a LIB file a static file?

   • The C runtime comes in both static and dynamic versions, so you can determine which version your program uses depending on particular needs. Turns out that .LIB files can be either static libraries (containing object files) or import libraries (containing symbols to allow the linker to link to a DLL). I'm wondering why this is so. good explanation!

   static libraries - DLL and LIB files - what and why? - Stack Overflow

   stackoverflow.com/questions/913691/dll-and-lib-files-what-and-why

   See all results for this question

   Is a so file a static library?

   • I know an .so file is a kind of dynamic library (lots of threads can share such libraries so there is no need to have more than one copy of it in memory). But what is the difference between .a and .la? Are these all static libraries? If dynamic libs have big advantages over static ones, why there are still lots of static libraries?

   linux - What's the difference between .so, .la and .a library files

   stackoverflow.com/questions/12237282/whats-the-difference-between-so-la-and-a-library-files

   See all results for this question

   What is a static link library?

   • There are two kinds. A static link library is a bag of .obj files, collected into a single file. The linker picks any chunks of code from the file when it needs to resolve an external identifier. But more relevant to DLLs, a LIB file can also be an import library.

   c++ - What is inside .lib file of Static library, Statically linked

   stackoverflow.com/questions/3250467/what-is-inside-lib-file-of-static-library-statically-linked-dynamic-library-an

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   What is a static library?

   • In computer science, a static library or statically linked library is a set of routines, external functions and variables which are resolved in a caller at compile-time and copied into a target application by a compiler, linker, or binder, producing an object file and a stand-alone executable.

   Static library - Wikipedia

   en.wikipedia.org/wiki/Static_library

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5. en.wikipedia.org › wiki › Static_libraryStatic library - Wikipedia

   en.wikipedia.org › wiki › Static_library

   • Cached

   In computer science, a static library or statically linked library is a set of routines, external functions and variables which are resolved in a caller at compile-time and copied into a target application by a compiler, linker, or binder, producing an object file and a stand-alone executable.

6. dev.to › iamkhalil42 › all-you-need-to-know-about-cAll you need to know about C Static libraries - DEV Community

   dev.to › iamkhalil42 › all-you-need-to-know-about-c

   • Cached

   Sep 4, 2020 · A static library is a file containing a collection of object files (*.o) that are linked into the program during the linking phase of compilation and are not relevant during runtime. As shown in the diagram above, when a program is compiled, the compiler generates an object file from a source file.

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7. learn.microsoft.com › en-us › cppWalkthrough: Create and use a static library (C++ ...

   learn.microsoft.com › en-us › cpp

   • Cached

   Oct 28, 2021 · This step-by-step walkthrough shows how to create a static library (.lib file) for use with C++ apps. Using a static library is a great way to reuse code. Rather than reimplementing the same routines in every app that requires the functionality, you write them one time in a static library and then reference it from the apps.

8. www.learncpp.com › cpp-tutorial › a1A.1 — Static and dynamic libraries – Learn C++ - LearnCpp.com

   www.learncpp.com › cpp-tutorial › a1

   • Cached

   When you compile a program that uses a static library, all the functionality of the static library that your program uses becomes part of your executable. On Windows, static libraries typically have a .lib extension, whereas on Linux, static libraries typically have an .a (archive) extension.

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10. medium.com › @bdov_ › https-medium-com-bdov-c-staticC Static Libraries — What, Why, and How? | by Brennan D ...

    medium.com › @bdov_ › https-medium-com-bdov-c-static

    • Cached

    Oct 6, 2018 · Static libraries are collections of object files that are linked into a program during the linking phase of compilation, and thus are not needed during runtime (in contrast, object files in...

11. dev.to › kristi › c-static-libraries-46c6C Static Libraries - DEV Community

    dev.to › kristi › c-static-libraries-46c6

    • Cached

    Mar 1, 2022 · A static library is an archive file containing object files that remain static until the program is recompiled. This static library can be used as a single entity in a linking phase of a program. Why do we use libraries? Using a static library means only one object file needs to be pulled in during the linking phase.