int

问题 What would be the different between void and int functions? When do i use which? Would void be used when just printing out a message or a variable value? like cout << value; Or would it just be text? And is int used when you actually do calculations within it? 回答1: void is used when you are not required to return anything from the function to the caller of the function. for eg. void no_return_fn() { cout<< "This function will not return anything" << endl; return; // returns nothing or void }

问题 I wanted to check whether input given is integer input or not. I did not wanted to store input in a string. After seeing several questions on stackoverflow and by hit and trial, I have created following code while(scanf("%d%c",&num,&a) != 2 || a != '\n') { printf("Please enter an integer only : "); if(a == '\n') scanf("%c",&a); else { while(a != '\n') scanf("%c",&a); } } It works but according to my understanding, the following should have also worked while(scanf("%d%c",&num,&a) != 2 || a !=

问题 I get this: warning C4244: 'initializing' : conversion from 'uintmax_t' to 'unsigned int', possible loss of data on: boost::shared_array<char> buffer( new char[file->size]); …and then this: warning C4244: 'argument' : conversion from 'uintmax_t' to 'size_t', possible loss of data on: boost::asio::write(*socket, boost::asio::buffer(buffer.get(), file->size)); Shall I be scared or it is ok? 回答1: Probably file->size is of type uintmax_t which is larger than the size_t that operator new[] takes

问题 The Message Passing Interface APIs always use int as a type for count variables. For instance, the prototype for MPI_Send is: int MPI_Send(const void* buf, int count, MPI_Datatype datatype, int dest, int tag, MPI_Comm comm); This may be a problem if the number of elements to be sent or received grows near or even beyond INT_MAX . Of course the issue may be solved lowering the value of count by either: splitting a single call into multiple calls defining an (unnecessary) aggregate MPI_Datatype

问题 Let's say I have an array that is long enough to access any of its index with int , is there any way to access the index of such an array with long ? And how the Java handle this kind of array? Example: int[] a = new int[]{1,5,2,4........9,2,1} Assume in the above array that 9,2,1 are at indices that are beyond the range of int (2 31 ). How would I access these elements? 回答1: You wouldn't - array indexes are always int values in Java. It doesn't allow for an array with more than Integer.MAX

问题 FIXED IN SWIFT 4.2 Details Xcode 9.2, Swift 4 Code extension BinaryFloatingPoint { func toInt() -> Int { // Eror if remove this block (I do not know why) // if let value = self as? CGFloat { // return Int(value) // } return Int(self) } } Error occurrence let float: Float = 2.38945 print("Float: \(float.toInt())") // No Error let double = Double(float) print("Double: \(double.toInt())") // No Error let cgfloat = CGFloat(float) print("CGFloat(): \(Int(cgfloat))") // No Error print(".toInt(): \

问题 I have the following html field, for which i need to check whether the input value is float or int, <p class="check_int_float" name="float_int" type="text"></p> $(document).ready(function(){ $('.check_int_float').focusout(function(){ var value = this.value if (value is float or value is int) { // do something } else { alert('Value must be float or int'); } }); }); So how to check whether a value is float or int in jquery. I need to find/check both cases, whether it is a float, or int, because

问题 I have a simple question that is confusing me. Goal : I want to read a given byte from a file (say the first byte) and make int x with the ASCII value of that byte. So, for example, if the byte/character is 'a', I want x to be 97 (= 61 in hex). I have the following reading the first byte of the file example.txt: #include <iostream> #include <fstream> #include <string> using namespace std; int main(){ unsigned int x; unsigned char b; ifstream myFile ("example.txt", ios::out | ios::binary);

问题 I have: int a = 2147483647; short b = (short)a; and I get b = -1 whereas I expect int32 to be converted to int16 ( short ). I expect to see some value and not -1 . Please someone help me with this. 回答1: Your int A is larger than the size of short. When you convert A to short, you get a 1 in the left most bit, which is going to indicate that it is a negative number. Since you're getting -1, I suppose you're getting 1s in all 16 bits, which is going to give you -2^15 + 2^14 + 2^13... + 2^0,

问题 I am trying to change the opacity of a color that I get of my theme with the next code: TypedValue typedValueDrawerSelected = new TypedValue(); getTheme().resolveAttribute(R.attr.colorPrimary, typedValueDrawerSelected, true); int colorDrawerItemSelected = typedValueDrawerSelected.data; I want that the colorDrawerItemSelected keeps the same color, buth its alpha should be 25%. I found some solutions getting the rgb color from the imageView, but I havent imageView. Thank you for your time. 回答1: