boolean

问题 I have a problem on checking the text and string. public boolean Isequals(Object c){ boolean check = false; if (c instanceof MyTextTwist){ MyTextTwist tt = (MyTextTwist)c; if (txtGuessPad.getText().equals(answer)) check = true;} return check; } this what i have so far. 回答1: Since your question is not very clear, i suggest these answers: 1st option - you want to get string from your JTextField: String text = txtGuessPad.getText(); 2nd option - you want to check if text contains only letter:

问题 There are lots of questions about this but I've not been able to solve my problem using the answers to any of them (after many, many attempts..) I'm working in vb.net creating an asp.net web application. I have an SqlDataSource and a GridView on my page. I want to change the DoNotMail boolean value represented by a Gridview checkbox and automatically update in the database if the checkbox is checked from 0 (False, Will Mail) to 1 (True, Won't Mail) here is the code I used. For the default

问题 I have to make a program that counts the number of the letter B in a string. I got that part already, but it also requires me to use a static method that returns true or false based on if the string has any Bs in it and i really don't see how to fit that part in. import java.util.Scanner; public class CountB { // write the static method “isThisB” here public static void main(String[] args) { Scanner keyboard = new Scanner(System.in); System.out.println("Enter a string: "); String w = keyboard

问题 I have to make a program that counts the number of the letter B in a string. I got that part already, but it also requires me to use a static method that returns true or false based on if the string has any Bs in it and i really don't see how to fit that part in. import java.util.Scanner; public class CountB { // write the static method “isThisB” here public static void main(String[] args) { Scanner keyboard = new Scanner(System.in); System.out.println("Enter a string: "); String w = keyboard

问题 I noticed an issue with java.lang.Boolean class that it can not parse nulls. I know it has the parseBoolean static method but as it's signature states it only accepts String and not an Object . In other words, it has the following signature: public static boolean parseBoolean(String s) but not: Boolean.parseBoolean(Object) What is the best way to check a Boolean value without falling on NullPointerException? 回答1: Try that approach: Boolean.TRUE.equals(yourObj); 回答2: If you want your parse to

问题 I'm a beginner programmer in C++ (currently), and I've got a conceptual question. I'm trying to filter a cin input to ensure that it is a one-or-two-digit integer between 01-04, and if it isn't, to produce an error and ask for a new input. I'm also using map to give the user a list of options that, upon valid selection, routes inputs (integers) through any of several methods to produce a relevant result, but I'll ask a more specific version of this question elsewhere. I found a snippet of

问题 I encounter a simple problem , I am trying to change the bool value of a class from another class but it is not happening, it returns NO . //before pushing other viewcontroller -(IBAction)editWOD { self.editGirlController= [[AddGirlsView alloc] init]; self.editGirlController.isEditModeON=YES; self.editGirlController.editgirls=girls; [self performSegueWithIdentifier:@"editModeGirls" sender:self]; } AddGirlsView .h @interface AddGirlsView : UIViewController { BOOL isEditModeON; } @property BOOL

问题 All this time my thinking of short circuit evaluations seems to be wrong. In javascript: var a = false, b = true, c=true; a && b || c; // Evaluates to true Compared to var a = false, b = true, c=true; a && (b || c); // Evaluates to true Why doesn't the VM stop when it sees that a is false? More explicit example: function a(){ console.log("I'm A"); return false; } function b(){ console.log("I'm B"); return true; } function c(){ console.log("I'm C"); return true; } a() && b() || c(); The output

问题 All this time my thinking of short circuit evaluations seems to be wrong. In javascript: var a = false, b = true, c=true; a && b || c; // Evaluates to true Compared to var a = false, b = true, c=true; a && (b || c); // Evaluates to true Why doesn't the VM stop when it sees that a is false? More explicit example: function a(){ console.log("I'm A"); return false; } function b(){ console.log("I'm B"); return true; } function c(){ console.log("I'm C"); return true; } a() && b() || c(); The output

问题 I'm a Python developer and I just started learning Rails, so this might be a noobish question. I found some surprising behavior in my code: <!-- render flash message array if set --> <% if flash[:notice].is_a? Array && !flash[:notice].empty? %> This results in the following error: undefined method `empty?' for nil:NilClass It seems like Ruby should not be calling .empty? in the second part of this clause. I confirmed that short-circuit evaluation works in other cases: # this is more what I