character

问题 I have a df such as: name <- rep(c("a","b","c"),5) QV.low <- runif(15, 2, 5) QV.med <- runif(15, 5.0, 7.5) QV.high <- runif(15, 7.5, 10) df <- as.data.frame(cbind(name, QV.low, QV.med,QV.high)) and a list of names: name.list <- c("a","b") I want to do an operation, eg: df %>% subset(name %in% name.list) %>% summarise(.,sum = sum(QV.low)) but I want to for each QV. variable via a loop. I tried: QV.list <- c("QV.low", "QV.med", "QV.high") for(qv in 1:length(QV.list)){ QV <- noquote(QV.list[qv])

问题 Code: #include <fstream> const wchar_t * testArray[] = { L"Wszystkie kategorie równoważne", L"Oczekiwane przepływy pieniężne", L"Risk i dojrzałość", L"Pozycja strategiczna i lata na rynku", L"Prawdopodobieństwo oszacowania" }; void FaultyFunction(void) { std::wofstream file("test.txt"); for (int i = 0 ; i < 100 ; ++i) { for (int j = 0 ; j < 5 ; ++j) { file << testArray[j] << L'\t'; } file << L'\n'; } } int main(void) { FaultyFunction(); return 0; } "test.txt" after execution: Wszystkie

问题 This question already has answers here : What is the equivalent to getch() & getche() in Linux? (6 answers) Closed 4 years ago . I'm trying to get a single character input from the user without the user having to press enter. I've tried this: #include <stdio.h> int main() { int input; for (;;) { input = getchar(); printf("%d\n", input); } } But not only does the user need to press enter, it also registers two presses (the input character and the newline character) ie: $ ./tests a 97 10 c 99

问题 I want to print the following output ***** **** *** ** * using recursive subroutine. And my code is as follows: PROGRAM PS IMPLICIT NONE CALL print_star(5, '*') CONTAINS RECURSIVE SUBROUTINE print_star(n, star) INTEGER :: n CHARACTER(LEN = *) :: star CHARACTER(LEN = *) :: new_star IF (n > 1) THEN new_star = star // '*' CALL print_star(n - 1, new_star) END IF print *, star END SUBROUTINE print_star END PROGRAM PS Then it return error: CHARACTER(LEN = *) :: new_star 1 Error: Entity with assumed

问题 The Character class in Java defines methods which check a given char argument for equality with certain Unicode chars or for belonging to some type category. These chars and type categories are named. As stated in given javadoc, examples for named chars are HORIZONTAL TABULATION , FORM FEED , ...; example for named type categories are SPACE_SEPARATOR , PARAGRAPH_SEPARATOR , ... However, being byte or int values instead of enums, the name of these types are "hidden" at runtime. So, is there a

问题 I would like to know whether the user pressed F1 or F2 or F3 or F4 or F5 or ESC and perform an action after that but I don't know how to get these keys. Can anyone help? 回答1: For Windows, there is the _getch function, which returns the bytes of a key code, one by one. You can get a function key that way, detecting it by the presence of certain codes: 0x00 or 0xe0 as shown in the example in [C\C++] - how get arrow keys(correctly) using getch()? . When _getch returns one of those, the next byte

问题 so my problem is that I need to get the user to enter a string . then they will enter a character that they want counted. So the program is supposed to count how many times the character they entered will appear in the string, this is my issue. If someone can give me some information as to how to do this, it'll be greatly appreciated. import java.util.Scanner; public class LetterCounter { public static void main(String[] args) { Scanner keyboard= new Scanner(System.in); System.out.println(

问题 I need to count the number of an input character there is in an input sentence. I am so close however I keep getting this error: countchar.cpp:19:19: error: empty character constant countchar.cpp: In function â: countchar.cpp:26:75: error: could not convert â from â to â #include <string> #include <fstream> #include <iostream> #include <algorithm> using namespace std; void WordOccurenceCount(string, int); int main() { char character; string sentence; char answer; string cCount; while(1) {

问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 6 years ago . Using JS, how can I detect if a special character is entered into an input field as it's typed? EDIT: Special character being defined as non-alpha/numeric character EDIT(2): If it helps anyone else, here's what I

问题 I am attempting to capture input from the user via scanf: char numStrings[5000]; printf("Enter string of numbers:\n\n"); scanf("%s", numStrings); However, the length of the string that is inputted is 5000 characters. The translation limit in c99 is 4095 characters. Do I need to instruct the user to break their input in half or is there a better work around that I cannot think of? 回答1: Do I need to instruct the user to break their input in half or is there a better work around that I cannot