java certification questions and answers

Beginners | Questions for this series of questions, every Java learner should understand. Of course, it doesn't matter if you just learn to play Java. If you think you have gone beyond beginners, but do not understand these questions, please return yourself to the ranks of b

that this stage will bring me higher expectations, of course, the interview when normal people will not remember the spelling of each parameter, I wrote this paragraph when I also turned over the manual. The answer to this section is less than 2%.PS: Add up to less than 100%, is because there are really few directly say do not know, or directly refused to answer = =#Analyze the second question: "What is the Thing":1. Objects that are not used.Analysis: The equivalent of no answer, the question

, char, Boolean, float, double 6, Math.Round (11.5) equals ___; Math.Round (-11.5) equals ___. Answer: The rounding of 11.5 is rounded to 12,-11.5-11 with rounding calculation. 7, the program string str1 = "Hello"; String str2 = "he" +new string ("Llo"); The result of System.out.println (STR1==STR2) is ______. Answer: false 8, the string is divided into two categories, one is the string constants, using the object of the _ _ _ class, and the other is a string variable, using the object of the _

Six big questions that Java beginners must understandFor the problems in this series, everyone who learns Java should understand. Of course, it doesn't matter if you just learn to play in Java. If you think you have surpassed the beginner, but do not understand these problems, please return yourself to the ranks of beg

second variable, it must be explicitly initialized. If you try to use it before it is initialized, the compiler will protest. If the initialized statement is in a try block or an if block, it must be assigned before the first use. That is, the compiler will also protest if the initialization statement is placed in a conditional judgment statement with only the If block, because execution may not conform to the judgment condition after the IF, so that the initialization statement is not executed

the execution has completed.Input Sample:3 31 1 1 2 0 1 2 1-1-11Sample output:7time limit: 500ms memory limit: 32000kb Import Java.util.scanner;public class Cellmachine {static Scanner in = new Scanner (system.in); static int width = 0;//width st atic int height = 0;//height static int[][] field_old;//old grid static int[][] field_new;//new mesh static int times;//steps Public stat IC void Main (string[] args) {//First enter two positive integers with a range of [3,102], which in turn represent