Skip to main content

C# Learning: strut


One of the types in .NET we haven’t talked about much is the struct.
struct is short for structure, and structs look a lot like objects.
They have fields and properties, just like objects. And you can even pass
them into a method that takes an object type parameter:
A struct looks like an object…
…but isn’t an object

public struct Dog {
public string Name;
public string Breed;
public Dog(string name, string breed) {
this.Name = name;
this.Breed = breed;
}
public void Speak() {
Console.WriteLine(“My name is {0} and I’m a {1}.”, Name, Breed);
}
}



But structs aren’t objects. They can have methods and fields, but
they can’t have finalizers. They also can’t inherit from other classes or
structs, or have classes or structs inherit from them.


Structs are best used for storing data, but the lack of inheritance and references can be a serious limitation.


But the thing that sets structs apart from objects more than almost anything else is that you copy them by value, not by reference. Which means values get copied; references get assigned.


When you create a struct, you’re creating a value type. What that means is when you use equals to set one struct variable equal to another, you’re creating a fresh copy of the struct in the new variable. So even though a struct looks like an object, it doesn’t act like one.



Comments

Popular posts from this blog

Quicksort implementation by using Java

 source: http://www.algolist.net/Algorithms/Sorting/Quicksort. The divide-and-conquer strategy is used in quicksort. Below the recursion step is described: 1st: Choose a pivot value. We take the value of the middle element as pivot value, but it can be any value(e.g. some people would like to pick the first element and do the exchange in the end) 2nd: Partition. Rearrange elements in such a way, that all elements which are lesser than the pivot go to the left part of the array and all elements greater than the pivot, go to the right part of the array. Values equal to the pivot can stay in any part of the array. Apply quicksort algorithm recursively to the left and the right parts - the previous pivot element excluded! Partition algorithm in detail: There are two indices i and j and at the very beginning of the partition algorithm i points to the first element in the array and j points to the last one. Then algorithm moves i forward, until an element with value greater or equal

Live - solving the jasper report out of memory and high cpu usage problems

I still can not find the solution. So I summary all the things and tell my boss about it. If any one knows the solution, please let me know. Symptom: 1.        The JVM became Out of memory when creating big consumption report 2.        Those JRTemplateElement-instances is still there occupied even if I logged out the system Reason:         1. There is a large number of JRTemplateElement-instances cached in the memory 2.     The clearobjects() method in ReportThread class has not been triggered when logging out Action I tried:      About the Virtualizer: 1.     Replacing the JRSwapFileVirtualizer with JRFileVirtualizer 2.     Not use any FileVirtualizer for cache the report in the hard disk Result: The japserreport still creating the a large number of JRTemplateElement-instances in the memory        About the work around below,      I tried: item 3(in below work around list) – result: it helps to reduce  the size of the JRTemplateElement Object        

Stretch a row if data overflows in jasper reports

It is very common that some columns of the report need to stretch to show all the content in that column. But  if you just specify the property " stretch with overflow' to that column(we called text field in jasper report world) , it will just stretch that column and won't change other columns, so the row could be ridiculous. Haven't find the solution from internet yet. So I just review the properties in iReport one by one and find two useful properties(the bold  highlighted in example below) which resolve the problems.   example: <band height="20" splitType="Stretch" > <textField isStretchWithOverflow="true" pattern="" isBlankWhenNull="true"> <reportElement stretchType="RelativeToTallestObject" mode="Opaque" x="192" y="0" width="183" height="20"/> <box leftPadding="2"> <pen lineWidth="0.25"/>