variable-assignment

问题 I'm testing an expression with two inequalities for the condition of a list comprehension. Is there a way to have assignments here and not duplicate that expression? (The following code doesn't work, but I wish it would) diagnose(Expertise,PatientSymptoms)-> {[CertainDisease|| {CertainDisease,KnownSymptoms}<-Expertise, C=length(PatientSymptoms)-length(PatientSymptoms--KnownSymptoms), C>=2, C<=5 ]}. 回答1: A way of writing it directly without a fun would be to use a begin ... end block ending

问题 The C++11 standard (5.17, expr.ass) states that In all cases, the assignment is sequenced after the value computation of the right and left operands, and before the value computation of the assignment expression. With respect to an indeterminately-sequenced function call, the operation of a compound assignment is a single evaluation As I understand it, all expressions which are a part of the given assignment will be evaluated before the assignment itself. This rule should work even if I

问题 Why do we see Python assignments with or ? For example: def my_function(arg_1=None, arg_2=0): determination = arg_1 or arg_2 or 'no arguments given!' print(determination) return determination When called with no arguments, the above function would print and return 'no arguments given!' Why does Python do this, and how can one best make best use of this functionality? 回答1: What the " or " expression does on assignment: We sometimes see examples of this in Python as a substitute for conditional

问题 #include<stdio.h> #include<conio.h> int main(){ char i; int c; scanf("%i",&c); scanf("%c",&i);// catch the new line or character introduced before x number printf("%i",i);// value of that character getch(); return(0); } The program will behave in the same way with the next variable declarations instead of the above variable declaration: this: int c; int *x; int i; or this: int *x; int c; int i; And only this way: c variable and a x pointer before the i variable. I know that those last

问题 As the title says I found such a sentence in some C lecture notes. I can't invent any example proving that sentence. In my opinion every of assignment operations is evaluated once, because when we want it to be evaluated more than once we put in in a loop. What am I missing then? I've searched but couldn't find an answer here on SO. 回答1: C says: (C99, 6.5.16.2p3) "A compound assignment of the form E1 op= E2 differs from the simple assignment expression E1 = E1 op (E2) only in that the lvalue

问题 I have a text file containing simulation data (60 columns, 100k rows): a b c 1 11 111 2 22 222 3 33 333 4 44 444 ... where in the first row are variable names, and beneath (in columns) is the corresponding data (float type). I need to use all these variables with their data in Python for further calculations. For example, when I insert: print(b) I need to receive the values from the second column. I know how to import data: data=np.genfromtxt("1.txt", unpack=True, skiprows = 1) Assign

问题 The code below works. Is there a way that is more convenient, if possible even a one-liner? const { nextUrl, posts } = await postService.getCommunityPosts(6); this.communityPosts = posts; this.nextUrl = nextUrl; I know about giving destructured properties aliases but I don't think that helps in this case. MDN doesn't say anything about that case. 回答1: You can assign to the properties of an existing object by giving aliases and encapsulating the assignment in parentheses (await codepen). const

问题 I was wondering if there was a way to assign a value and print the value to the console succinctly. x <- 1:5; x This is how I would presently do this, but I was wondering if there was a way to do it in one statement. 回答1: You can try: (x <- 1:5) or print(x <- 1:5) though that won't work for things like (names(x) <- letters[1:5]) though for that specific example you can do: (x <- setNames(x, letters[1:5])) 来源： https://stackoverflow.com/questions/22003683/simultaneous-variable-assignment-and

问题 Consider the following example illustrating the question (it was just built to explain the question, but I saw similar code in books as well in real projects): package main import ( "strconv" "fmt" "log" ) func main() { n1, err := strconv.Atoi("1") if err != nil { log.Panicf("%v", err) } n2, err := strconv.Atoi("2") if err != nil { log.Panicf("%v", err) } // err := fmt.Errorf("new error") <- line 1 // n1, err := strconv.Atoi("3") <- line 2 fmt.Printf("n1 = %d, n2 = %d\n", n1, n2) } The

问题 In C#, if I have a List<T> , and I have an object of type T , how can I replace a specific item in the List<T> with the object of type T ? Here is what I have tried: List<CustomListItem> customListItems = new List<CustomListItem>(); CustomListItem customListItem1 = new CustomListItem() { name = "Item 1", date = DateTime.MinValue}; CustomListItem customListItem2 = new CustomListItem() { name = "Item 2", date = DateTime.MinValue }; CustomListItem customListItem3 = new CustomListItem() { name =