Java中的println和printf的区别在于:println是用于输出参数内容,然后换行,其参数个数固定为一个.printf是用于输出带各种数据类型的占位符的参数,其参数个数是不定的.…

System.out.printf("%d\n", 1000000000000000000L); …

[转自]http://heidian.iteye.com/blog/404632 目前printf支持以下格式:            %c        单个字符            %d        十进制整数            %f        十进制浮点数            %o        八进制数            %s        字符串            %u        无符号十进制数            %x        十六进制数      …

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http://www.onjava.com/pub/a/onjava/2001/05/30/optimization.htmlComparing the performance of LinkedLists and ArrayLists (and Vectors) (Page last updated May 2001, Added 2001-06-18, Author Jack Shirazi, Publisher OnJava). Tips: ArrayList is faster than…

$ps -Lp 179093 cu | more USER PID LWP %CPU NLWP %MEM VSZ RSS TTY STAT START TIME COMMAND admin 179093 179093 0.0 383 54.5 5803448 4572012 ? Sl Aug05 0:00 java admin 179093 179097 0.0 383 54.5 5803448 4572012 ? Sl Aug05 0:01 java admin 179093 179100 0…

How to Use DTrace to Troubleshoot Java Native Memory Problems on Oracle Solaris 11 Hands-On Labs of the System Admin and Developer Community of OTN by Wang Yu, Vincent Liu, and Gary Wang This lab will introduce the basic concepts of DTrace and provid…

Summary: This page is a printf formatting cheat sheet. I originally created this cheat sheet for my own purposes, and then thought I would share it here. A cool thing about the printf formatting syntax is that the specifiers you can use are very simi…

一.需求:计算网页访问量前三名 import org.apache.spark.rdd.RDD import org.apache.spark.{SparkConf, SparkContext} /** * 需求:计算网页访问量前三名 * 用户:喜欢视频 直播 * 帮助企业做经营和决策 * * 看数据 */ object UrlCount { def main(args: Array[String]): Unit = { //1.加载数据 val conf:SparkConf = new Spa…

java中有三种方式向控制台输入信息,分别是print,printf,println,现在简单介绍一下他们之间的异同. printf主要是继承了C语言的printf的一些特性,可以进行格式化输出 print就是一般的标准输出,但是不换行 println和print基本没什么差别,就是最后会换行 看一下他们的效果: print:…