field

问题 valid code: interface Int1{ String str = "123"; } class Pparent{ String str = "123"; } class F extends Pparent implements Int1{ } invalid code add main method to F class: class F extends Pparent implements Int1{ public static void main(String[] args) { System.out.println(str); } } outs Exception in thread "main" java.lang.Error: Unresolved compilation problem: The field str is ambiguous at test.core.F.main(NullReferenceTest.java:45) I don't see striking differs beetwen both variants. I

问题 valid code: interface Int1{ String str = "123"; } class Pparent{ String str = "123"; } class F extends Pparent implements Int1{ } invalid code add main method to F class: class F extends Pparent implements Int1{ public static void main(String[] args) { System.out.println(str); } } outs Exception in thread "main" java.lang.Error: Unresolved compilation problem: The field str is ambiguous at test.core.F.main(NullReferenceTest.java:45) I don't see striking differs beetwen both variants. I

问题 I'm having a Scala trait A with an abstract method trait A[T] { def self: T } Now it happened me that I want to extends a Java class not under my control with a field with the same name: public class B<T> { protected T self; } I'd like to have a class C defined like class C[T] extends B[T] with A[T] { override def self: T = /* the field `self` of `B` ??? */ } Is it possible to access the field B.self somehow so that it doesn't resolve to the method A.self instead? Is it even possible to have

问题 I have the following to disallow spaces function nospaces(t){ if(t.value.match(/\s/g)){ alert('Username Cannot Have Spaces or Full Stops'); t.value=t.value.replace(/\s/g,''); } } HTML <input type="text" name="username" value="" onkeyup="nospaces(this)"/> It works well for spaces but how can I also disallow full stops as well? 回答1: Try this function nospaces(t){ if(t.value.match(/\s|\./g)){ alert('Username Cannot Have Spaces or Full Stops'); t.value=t.value.replace(/\s/g,''); } } 回答2: Below is

问题 how to get a list of all orders in the table except (orders which has been referenced and type of -1) orders Table: id | reference_id | type ---------------------------------- 1 | | 1 ---------------------------------- 2 | | 1 ---------------------------------- 3 | 1 | -1 ---------------------------------- something like: list = ArrayList(); if( order.type > 0 ){ if( order.id != other_order.reference_id ) list.add(order) } how to do this in MySQL Statement? also the same result of this

问题 I would like to ask how to achieve the following in Scala. Consider scala> case class C(i:Int) defined class C scala> val c = C(1) c: C = C(1) Given a field of interest, in this case scala> val fname = "i" fname: String = i we would like to retrieve the original value and type of field i in c. A first, naive, attempt included the following, scala> val f = c.getClass.getDeclaredField(fname) f: java.lang.reflect.Field = private final int C.i scala> f.setAccessible(true) scala> f.getType res3:

问题 Why isn't it possible to declare a class constant filed of type Lambda Expression . I want Something like this: class MyClass { public const Expression<Func<string,bool>> MyExpr = (string s) => s=="Hello!"; } But I get the compile error: Expression cannot contain anonymous methods or lambda expressions 回答1: This is just a limitation of C# and CLR. Only primitive numeric values, string literals and null can be used as a value of a constant field. Expression trees are represented as a normal

问题 I came across some code and cannot understand a certain aspect of it although I have done some extensive searching! My question is: Why are parenthesis used in the middle of a method call? package com.zetcode; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.SwingUtilities; public class QuitButtonExample extends JFrame { public QuitButtonExample() { initUI(); } private

问题 Say i have a property in a class: Vector3 position{get; set;} So i create an instance of that class somewhere and now i want to change position.x, that would be impossible now because the getter and setter set and get the whole object. So i have to make a temporary Vector3 change its values and then assign it. Normally i would make position a public field so that problem would be solved. But i cant do it in this case because position is an implementation of an interface and interfaces cant

问题 So as I have learned since this post: How to stretch a text field relative to data width in Jasper Reports it is not possible to stretch the width of text fields. So I am trying to establish now whether it is possible to embed static text within a text field? I need to achieve a scenario something like this: "You're current employer [non-fixed width text] will contact you soon." Can anyone suggest a way to do this in Jasper? I'm all out of ideas. 回答1: You want a single Text Field with a value