variable-assignment

问题 I have declared four variables [a=1,b=2,c=3,d=0] in python and swapping them in one line code using ',' and '=' (Simple Assignment Operator). I have got multiple Answers and got confused. please help me... Case 1: a=1 b=2 c=3 d=0 a=a,b=b,c print "a = " + str(a) print "b = " + str(b) print "c = " + str(c) print "d = " + str(d) Output of Case 1: a = 2 b = 3 c = 3 d = 0 Case 2: a=1 b=2 c=3 d=0 b=a,b=b,c print "a = " + str(a) print "b = " + str(b) print "c = " + str(c) print "d = " + str(d)

问题 As it is MyClass x = 120; , is it possible to create such a custom class? If so, how can I do that? 回答1: It's generally considered a bad idea to use implicit operators, as they are, after all, implicit and run behind your back. Debugging code littered with operator overloads is a nightmare. That said, with something like this: public class Complex { public int Real { get; set; } public int Imaginary { get; set; } public static implicit operator Complex(int value) { Complex x = new Complex();

问题 Sample code: int ar[3]; ............ ar[0] = 123; ar[1] = 456; ar[2] = 789; Is there any way to init it shorter? Something like: int ar[3]; ............ ar[] = { 123, 456, 789 }; I don't need solution like: int ar[] = { 123, 456, 789 }; Definition and initialization must be separate. 回答1: What you are asking for cannot be done directly. There are, however different things that you can do there, starting from creation of a local array initialized with the aggregate initialization and then

问题 I'm beginner with tensorflow. I created this tensor z = tf.zeros([20,2], tf.float32) and I want to change the value of index z[2,1] and z[2,2] to 1.0 instead of zeros. How can I do that? 回答1: What you exactly ask is not possible for two reasons: z is a constant tensor, it can't be changed. There is no z[2,2] , only z[2,0] and z[2,1] . But assuming you want to change z to a variable and fix the indices, it can be done this way: z = tf.Variable(tf.zeros([20,2], tf.float32)) # a variable, not a

问题 I am trying to understand how variables work in python. Say I have an object stored in the variable a : >>> a = [1, 2, 3] If I assign a to b , both point to the same object: >>> b = a >>> b is a True But if I reassign a or b , that's no longer true: >>> a = {'x': 'y'} >>> a is b False The two variables now have different values: >>> a {'x': 'y'} >>> b [1, 2, 3] I don't understand why the variables are different now. Why is a is b no longer true? Can someone explain what's going on? 回答1:

问题 Recently I've time off of school for a few days and wanted to do a small program(s) experiment in C++ dealing with memory address. I wanted to see is that if a currently running program (Let call it Program A) that created a pointer to an int object in the heap, can be seen by another program and be modified (Program B). So for Program A, this is my basic code: // Program A #include <iostream> using namespace std; int main() { // Pointer to an int object in the heap int *pint = new int(15); /

问题 I have some code like this: def foo(): bar = initial_bar = Bar() while True: next_bar = Bar() bar.next_bar = next_bar bar = next_bar return initial_bar The intent being that a chain of Bar s is formed which can be followed, linked-list style. This was all very well; but through some misguided notion I wanted to cut it down by a line, compounding the assignments at the end of the loop into a single line. def foo(): bar = initial_bar = Bar() while True: next_bar = Bar() bar = bar.next_bar =

问题 Assuming I have a struct S of size 0x1 with the fields a and b , what is the most elegant way to add a field c to it? Usually I am able to do it like this: S = struct('a',0,'b',0); %1x1 struct with fields a,b S.c = 0 However, if I receive an empty struct this does not work anymore: S = struct('a',0,'b',0); S(1) = []; % 0x1 struct with fields a,b S.c = 0; % A dot name structure assignment is illegal when the structure is empty. % Use a subscript on the structure. I have thought of two ways to

问题 I've been asking questions about what I think might be solutions, but somebody pointed out that I'm falling into the XY problem and that I should just ask about my exact problem. I have a struct that I want other people to be able to use in their own programs. It needs to be possible to implicitly convert to this type from other existing types but at the same time some information needs to persists after this assignment. Here's a simple example of the issue: using System; public struct

问题 I was reviewing some code and I came across this: public static doSomething(String myString, String myString2) { //Stuff } public static doAnotherThing(String myString) { return doSomething(myString = myString != null ? myString.toLowerCase(): myString, null) } How is this working exactly?, I know the .toLowerCase resulting string is assigned to myString (yes I know bad practice since you are not supposed to reassign method parameters in fact they should be final), but I am not quite sure how