stringbuilder

Is there an implicit method to convert scala.collection.mutable.StringBuilder to java.lang.StringBuilder? I am using a Java library (JCommander) in which one of the methods ( usage ) takes a java.jang.StringBuilder argument. You can't start with a Scala StringBuilder and then obtain the Java version. You can, however, wrap a java.lang.StringBuilder in the Scala version. So: val jsb = new java.lang.StringBuilder(); val sb = new StringBuilder(jsb); // Do Scala-y stuff with sb JCommander.whatever.usage(jsb); // Do more Scala-y stuff Since--not a guarantee, but true in practice right now (2.8, 2.9

This question already has an answer here: Is Java “pass-by-reference” or “pass-by-value”? 86 answers I do not understand why System.out.println(name) outputs Sam without being affected by the method's concat function, while System.out.println(names) outputs Sam4 as a result of the method's append method. Why is StringBuilder affected and not String? Normally, calling methods on a reference to an object affects the caller, so I do not understand why the String result remains unchanged. Thanks in advance public static String speak(String name) { name = name.concat("4"); return name; } public

1、均可对字符串进行修改，但StringBuffer和StringBuilder类的对象进行多次修改时，不产生新的未使用对象。 　　String 的底层是用final修饰的char数组，变量的内容不可变——内存占用高，资源利用率低； 　　StringBuffer和StringBuilder类 则继承了AbstractStringBuilder类，其未使用final修饰char数组，变量内容动态更新——无效数组等待垃圾回收，减少资源占用; 2、StringBuilder相较于StringBuffer有速度优势。 3、StringBuilder和StringBuffer最大的区别是StringBuilder不是线程安全（不能同步访问）。 　　StringBuffer在拼接字符串时通过使用同步锁，实现线程安全； 　　StringBuilder未使用同步锁机制，故效率高于Stringbuffer; 来源： https://www.cnblogs.com/yangjuanjuan/p/11887547.html

This question already has an answer here: StringBuilder vs String concatenation in toString() in Java 18 answers String concatenation in Java - when to use +, StringBuilder and concat [duplicate] 9 answers As I understand it, when I do String baz = "foo" + "bar" + "123" the Java compiler internally replaces the expression with a StringBuilder . However our Java teacher told us that it is good practice to always use a StringBuilder explicitly... Am I correct in assuming I will only need to explicitly use StringBuilder when concatenating inside loops as indicated in an answer to Stack Overflow

This question already has an answer here: How to split a string in Java 34 answers Well the question is very simple. Lets say there is a StringBuilder sb Inside of sb numbers like this: "25 9631 12 1895413 1 234564" How to get those numbers one by one and initialize them into an ArrayList<Integer> list or to be more specific is it possible? Thanks for checking! Try to split that string like: String[] numbers = sb.toString().split(" ");//if spaces are uneven, use \\s+ instead of " " for (String number : numbers) { list.add(Integer.valueOf(number)); } Well my solution may not be the best here ,

摘自： https://www.cnblogs.com/zn19961006/p/11869182.html java基础阶段几个必会面试题 目录 1.说出你对面向对象的理解 在我理解,面向对象是向现实世界模型的自然延伸，这是一种“万物皆对象”的编程思想。在现实生活中的任何物体都可以归为一类事物，而每一个个体都是一类事物的实例。面向对象的编程是以对象为中心，以消息为驱动，所以程序=对象+消息。 面向对象有三大特性，封装、继承和多态。 封装就是将一类事物的属性和行为抽象成一个类，使其属性私有化，行为公开化，提高了数据的隐秘性的同时，使代码模块化。这样做使得代码的复用性更高。 继承则是进一步将一类事物共有的属性和行为抽象成一个父类，而每一个子类是一个特殊的父类--有父类的行为和属性，也有自己特有的行为和属性。这样做扩展了已存在的代码块，进一步提高了代码的复用性。 如果说封装和继承是为了使代码重用，那么多态则是为了实现接口重用。多态的一大作用就是为了解耦--为了解除父子类继承的耦合度。如果说继承中父子类的关系式IS-A的关系，那么接口和实现类之之间的关系式HAS-A。简单来说，多态就是允许父类引用(或接口)指向子类(或实现类)对象。很多的设计模式都是基于面向对象的多态性设计的。 2.JVM的内存区及其GC算法 参考： https://blog.csdn.net/anjoyandroid

Java StringBuffer和StringBuilder类 当字符串需要修改的时候使用StringBuffer和StringBuilder类 StringBuffer和StringBuilder类的区别 ​ StringBuffer：速度快，不是线程安全的 ​ StringBuilder：速度慢，线程安全 StringBuffer方法： 1、append()：追加字符串 2、reverse()：逆序 3、delete(start,end)：删除字符串 4、insert(index,string)：插入字符串 5、replace(start,end,str)：替换字符串 6、capacity()：返回当前容量 7、getChars()：截取字符串 余下的与String方法一样 来源： https://www.cnblogs.com/Mr-l/p/11875623.html

In my application I build an XML file with this code using StringBuilder : StringBuilder sb = new StringBuilder(); sb.Append("<?xml version=\"1.0\" encoding=\"utf-8\"?>" + Environment.NewLine); sb.Append(String.Format("<{0}>{1}", _pluralCamelNotation, Environment.NewLine)); for (int index = 0; index < 3; index++) { sb.Append(String.Format("\t<{0}>{1}", _singularCamelNotation, Environment.NewLine)); foreach (DataType dataType in _allDataTypes) { sb.Append(String.Format("\t\t<{0}>{2}</{0}>{1}", dataType.CamelCaseNotation, Environment.NewLine, dataType.GetDummyData())); } sb.Append(String.Format(