if-statement

问题 This question already has answers here : Why is “if not someobj:” better than “if someobj == None:” in Python? (9 answers) Closed 5 years ago . if not start: new.next = None return new what does "if not" mean? when will this code execute? is it the same thing as saying if start == None: then do something? 回答1: if is the statement. not start is the expression, with not being a boolean operator. not returns True if the operand ( start here) is considered false . Python considers all objects to

问题 A button in my app gets all the text you enter in 8 text fields and sends it to a table. I need code so that you need to fill in ALL fields before you can send the info. How do I write the if statement? This is the code for the add info button: private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { DefaultTableModel model = (DefaultTableModel) jTable1.getModel(); model.addRow(new Object[]{jTextField1.getText(), jTextField2.getText(), jTextField3.getText(), jTextField4.getText(

问题 I have here a rather simple rock, paper, scissors program where I am having some trouble with if statements. For some reason, when I enter rock, paper, or scissors (True Values), the program always performs if 'rock' or 'paper' or 'scissors' not in player: print("That is not how you play rock, paper, scissors!") for some reason. The complete program is as below. computer = ['rock', 'paper', 'scissors'] com_num = randint(0,2) com_sel = computer[com_num] player = input('Rock, paper, scissors GO

问题 This question already has answers here : Create Object in if-statement and use it later (3 answers) Closed 3 years ago . I'm trying to make a simple program for a bank account. I have created a class called Bank to make and instance and in the main class, where the main method is, I have made an if statement which will create an instance of the class "Bank" depending on the conditions met. The problem is that I can use the instance methods, which is outside the if statement. I have created

问题 I've been making a basic calculator with Python and I have come across this issue. After the calculations are made "Invalid Number" always prints and then the pause happens. I think it has something to do with the newline breaking the if block but I'm not sure. Any help will be appreciated. Thanks in advance. def badnum(): print("Invalid Number") print("Press enter to continue") input("") def main(): print("Select an action ") print("1.) Add") print("2.) Subtract") print("3.) Multiply") print

问题 This question already has answers here : Double structural equality operators: if(a==b==c) (2 answers) Closed 6 years ago . I've got 3 random numbers (in this specific case between 1 and 7 but it doesn't really matter). I want to check whether I got "three of a kind" by using if (x==y==z) { code } The problem is that when x==y and z==1 x==y==z will return true. How do I check whether x, y and z actually got the SAME value? Example: 5==5==1 will return true, how do I check for 5==5==5

问题 This question already has answers here : Double structural equality operators: if(a==b==c) (2 answers) Closed 6 years ago . I've got 3 random numbers (in this specific case between 1 and 7 but it doesn't really matter). I want to check whether I got "three of a kind" by using if (x==y==z) { code } The problem is that when x==y and z==1 x==y==z will return true. How do I check whether x, y and z actually got the SAME value? Example: 5==5==1 will return true, how do I check for 5==5==5

问题 package harry; import java.util.Scanner; public class harry { public static void main(String[] args) { String Harr = ("Harry"); Scanner name = new Scanner(System.in); System.out.println("Enter your name"); name.nextLine(); if(name.equals("Harry")) { System.out.println("She hates you"); } else if (name.equals("Nick")) { System.out.println("She loves you"); } } } In this code, I am trying to write the following: If the name is “Harry”, it should print “She hates you” If the name is “Nick”, it

问题 The problem is basically about to generate a arithmetic expression from a given 'n' numbers , and the expression should be divisible by 101. we can only have +,-,* operators and expression is left associative. I have tried all the available solution on , that are already mentioned on stack overflow, like closing the expressions with else and many more bool calci(int a[],int n,int sum,int pos,char operato[],deque<int>&q,deque<char>&qc) { if(sum%101==0) { //cout<<"sum:"<<sum<<endl; return true;

问题 The problem is basically about to generate a arithmetic expression from a given 'n' numbers , and the expression should be divisible by 101. we can only have +,-,* operators and expression is left associative. I have tried all the available solution on , that are already mentioned on stack overflow, like closing the expressions with else and many more bool calci(int a[],int n,int sum,int pos,char operato[],deque<int>&q,deque<char>&qc) { if(sum%101==0) { //cout<<"sum:"<<sum<<endl; return true;