How do I do a deep copy of a 2d array in Java?
Yes, you should iterate over 2D boolean array in order to deep copy it. Also look at java.util.Arrays#copyOf methods if you are on Java 6. I would suggest the next code for Java 6:
arrays
Convert array of strings into a string in Java
Java 8+ Use String.join(): Note that arr can also be any Iterable (such as a list), not just an array. If you have a Stream, you can use the joining collector: Legacy (Java 7 and earlier) Alternatively, if you just want a “debug-style” dump of an array: Note that if you’re really legacy (Java 1.4 and earlier) you’ll need to replace StringBuilder there with StringBuffer. Android … Read more
Fastest way to duplicate an array in JavaScript – slice vs. ‘for’ loop
There are at least 6 (!) ways to clone an array: loop slice Array.from() concat spread operator (FASTEST) map A.map(function(e){return e;}); There has been a huuuge BENCHMARKS thread, providing following information: for blink browsers slice() is the fastest method, concat() is a bit slower, and while loop is 2.4x slower. for other browsers while loop is the fastest method, since those browsers don’t have internal optimizations for slice and concat. This remains … Read more
Print ArrayList
I have an ArrayList that contains Address objects. How do I print the values of this ArrayList, meaning I am printing out the contents of the Array, in this case numbers. I can only get it to print out the actual memory address of the array with this code:
How do I get an empty array of any size in python?
If by “array” you actually mean a Python list, you can use or
How to convert an Object {} to an Array [] of key-value pairs in JavaScript
You can use Object.keys() and map() to do this
In Java, how to append a string more efficiently?
Use StringBuilder class. It is more efficient at what you are trying to do.
When will the worst case of Merge Sort occur?
The worst case of merge sort will be the one where merge sort will have to do maximum number of comparisons. So I will try building the worst case in bottom up manner: Suppose the array in final step after sorting is {0,1,2,3,4,5,6,7} For worst case the array before this step must be {0,2,4,6,1,3,5,7} because here left subarray={0,2,4,6} and right … Read more
what’s difference between array and tuple
Tuple A tuple is a grouping of unnamed, ordered values. Each value in a tuple does not need to be the same type. Array An array is mutable collection. They are very efficient to create, but must always be a single type.
Correct way of looping through C++ arrays
In C/C++ sizeof. always gives the number of bytes in the entire object, and arrays are treated as one object. Note: sizeof a pointer–to the first element of an array or to a single object–gives the size of the pointer, not the object(s) pointed to. Either way, sizeof does not give the number of elements in the array (its length). To get the … Read more