I have to ask a question in return: is your GenSet “checked” or “unchecked”? What does that mean? Checked: strong typing. GenSet knows explicitly what type of objects it contains (i.e. its constructor was explicitly called with a Class<E> argument, and methods will throw an exception when they are passed arguments that are not of … Read more
Use like this. List<String> stockList = new ArrayList<String>(); stockList.add(“stock1”); stockList.add(“stock2”); String[] stockArr = new String[stockList.size()]; stockArr = stockList.toArray(stockArr); for(String s : stockArr) System.out.println(s);
In your example, it is because you can’t have a List of a primitive type. In other words, List<int> is not possible. You can, however, have a List<Integer> using the Integer class that wraps the int primitive. Convert your array to a List with the Arrays.asList utility method. Integer[] numbers = new Integer[] { 1, … Read more
List<String> list = ..; String[] array = list.toArray(new String[0]); For example: List<String> list = new ArrayList<String>(); //add some stuff list.add(“android”); list.add(“apple”); String[] stringArray = list.toArray(new String[0]); The toArray() method without passing any argument returns Object[]. So you have to pass an array as an argument, which will be filled with the data from the list, … Read more
By default, the sort method sorts elements alphabetically. To sort numerically just add a new method which handles numeric sorts (sortNumber, shown below) – var numArray = [140000, 104, 99]; numArray.sort(function(a, b) { if( a === Infinity ) return 1; else if( isNaN(a)) return -1; else return a – b; }); console.log(numArray); Documentation: Mozilla Array.prototype.sort() … Read more
Warning: Cannot modify header information – headers already sent Happens when your script tries to send an HTTP header to the client but there already was output before, which resulted in headers to be already sent to the client. This is an E_WARNING and it will not stop the script. A typical example would be … Read more
Here’s a summary of Dimitris Andreou’s link. Remember sum of i-th powers, where i=1,2,..,k. This reduces the problem to solving the system of equations a1 + a2 + … + ak = b1 a12 + a22 + … + ak2 = b2 … a1k + a2k + … + akk = bk Using Newton’s identities, … Read more
Original answer, but costly (O(n)): array_shift(array_values($array)); In O(1): array_pop(array_reverse($array)); Other use cases, etc… If modifying (in the sense of resetting array pointers) of $array is not a problem, you might use: reset($array); This should be theoretically more efficient, if a array “copy” is needed: array_shift(array_slice($array, 0, 1)); With PHP 5.4+ (but might cause an index … Read more
You can use the indexOf method like this: var index = array.indexOf(item); if (index !== -1) { array.splice(index, 1); } Note: You’ll need to shim it for IE8 and below var array = [1,2,3,4] var item = 3 var index = array.indexOf(item); array.splice(index, 1); console.log(array)
Executive summary: int a[17]; size_t n = sizeof(a)/sizeof(a[0]); Full answer: To determine the size of your array in bytes, you can use the sizeof operator: int a[17]; size_t n = sizeof(a); On my computer, ints are 4 bytes long, so n is 68. To determine the number of elements in the array, we can divide … Read more