How to Dynamically Store Strings in a Two-Dimensional Array in C

Learn how to dynamically allocate memory for storing strings from a file in C. This guide details common issues and provides a working code example. --- This video is based on the question https://stackoverflow.com/q/62521622/ asked by the user 'Henry' ( https://stackoverflow.com/u/5700981/ ) and on the answer https://stackoverflow.com/a/62521695/ provided by the user 'MikeCAT' ( https://stackoverflow.com/u/4062354/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions. Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Store in a two-dimensional array strings from a file using dynamic memory allocation Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l... The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license. If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com. --- Storing Strings from a File in a Two-Dimensional Array in C When working with files in C, one common task is to read strings and store them in a two-dimensional array. However, dynamically handling memory for these strings can be tricky. In this guide, we'll explore an example that reads from a file, words.txt, which contains a list of numbers in Spanish, and how to properly store this data in a dynamically allocated array. The Problem You have a file named words.txt that contains the strings: [[See Video to Reveal this Text or Code Snippet]] The objective is to read these strings and store them in a dynamically allocated two-dimensional array. However, you might encounter a few issues along the way, such as memory allocation errors and incorrect reading of file data. Key Issues to Address File Reading Error: Forgetting to pass the file pointer to fscanf() can lead to failure in reading the file. Dynamic Memory Management: To handle strings of dynamic lengths, you need to properly manage memory to avoid overruns and leaks. Storing Variable Numbers of Strings: Ensuring that your program can handle any number of strings, regardless of how many are in the file. The Solution Let's go over a working code solution that addresses the issues mentioned above, ensuring we can dynamically read and store strings from the file. The Code Here's the complete example code for reading strings and storing them in a two-dimensional dynamically allocated array. [[See Video to Reveal this Text or Code Snippet]] Explanation of the Code Memory Allocation: We start with char **mystring = NULL; to initially define our pointer that will hold the strings. We use malloc to allocate memory for each string, ensuring each string has a set maximum length of 20 characters. Reading Strings: The loop continues until no more strings are read. The fscanf(fich, "%19s", next) carefully ensures we read up to 19 characters (leaving space for the null terminator), preventing buffer overruns. Dynamic Resizing: The realloc function is used to resize the memory allocated to mystring every time we read another string, accommodating any number of strings present in the file. Memory Management: It’s crucial to free up the memory allocated to prevent memory leaks. After storing strings, we release the memory allocated for each string and then for the array itself. Conclusion By following this guide, you should now be able to read strings from any file and store them dynamically in a two-dimensional array in C. Remember to always handle memory carefully and check your file operations to avoid errors. Happy coding!