java如何修改,从而不需要补全
问题遇到的现象和发生背景
import java.util.Scanner;
public class Histogram{
private static final int SENTINAL = -999; // sentinal value to signal endo of input
private static final int MAX_NUMBERS = 20; // maximum number of numbers to input
private static final double UPPER_BOUND = 100.0; // largest numbers accepted as data
private static final double LOWER_BOUND = 0.0; // smallest numbers accepted as adata
private static final int NUM_BINS = 10; // number of bins in range [0..100]
private static final int BIN_SIZE = 100/NUM_BINS; // size of each bin
/*
* Method to show an example of using StringBuilder.
*
* You will also notice that this method is called from the
* main function.
*
*/
public static String getHeaderAsString( String me ) {
// Create an instance of the StringBuilder class
// which allows us to create an object of
// a series of strings that can then be converted
// into one large string via the toString method.
//
StringBuilder sb=new StringBuilder();
sb.append( System.getProperty("line.separator") );
sb.append( "Welcome to the Histogram Program " + me + "!" );
me = getFirstName(me);
sb.append( System.getProperty("line.separator") );
sb.append( System.getProperty("line.separator") );
sb.append( "This program will print out a histogram of the numbers" );
sb.append( System.getProperty("line.separator") );
sb.append( "input by you " + getFirstName(me) + "." );
sb.append( System.getProperty("line.separator") );
sb.append( System.getProperty("line.separator") );
sb.append( "Please enter up to " + MAX_NUMBERS + " doubles or " + SENTINAL + " to stop input!" );
sb.append( System.getProperty("line.separator") );
return sb.toString();
}
/*
* Method to return the first name of the user in case
* the full name was entered.
*/
public static String getFirstName(String name ) {
// Note that add the " " to string to be sure
// there is something to split
return (name+" ").split(" ")[0];
}
/*
* local main test driver
*
*/
public static void main(String[] args) {
// Connect to the keyboard as the input stream
Scanner userInput = new Scanner( System.in );
System.out.print( "And who am I working with today? " );
String user = userInput.nextLine();
String heading = getHeaderAsString( user );
// Print out welcome message
System.out.println( heading );
// Call the method which prompts the user
// to input the numbers that will be used
// to build the histogram.
double[] numbers = inputNumbers( userInput );
// Call the method to reate the array histogram
int[] histogram = calculateHistogram( numbers );
// Print the historgram
System.out.println( toString( histogram ) );
}
public static int[] calculateHistogram(double []numbers){
int histogram[] = new int[NUM_BINS];
//looping through numbers array
for (int i = 0; i < numbers.length; i++) {
//incrementing the appropriate bins counter based on value
if (numbers[i]<=LOWER_BOUND+BIN_SIZE&& LOWER_BOUND+BIN_SIZE1;
}else if (numbers[i]<=LOWER_BOUND+(2*BIN_SIZE)&& LOWER_BOUND+(2*BIN_SIZE)<=UPPER_BOUND){
histogram[NUM_BINS-(NUM_BINS-1)]+=1;
}else if (numbers[i]<=LOWER_BOUND+(3*BIN_SIZE)&& LOWER_BOUND+(3*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-2)]+=1;
}else if (numbers[i]<=LOWER_BOUND+(4*BIN_SIZE)&& LOWER_BOUND+(4*BIN_SIZE)<=UPPER_BOUND){
histogram[NUM_BINS-(NUM_BINS-3)]+=1;
}else if (numbers[i]<=LOWER_BOUND+(5*BIN_SIZE)&& LOWER_BOUND+(5*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-4)]+=1;
} else if (numbers[i]<=LOWER_BOUND+(6*BIN_SIZE)&& LOWER_BOUND+(6*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-5)]+=1;
} else if (numbers[i]<=LOWER_BOUND+(7*BIN_SIZE)&& LOWER_BOUND+(7*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-6)]+=1;
} else if (numbers[i]<=LOWER_BOUND+(8*BIN_SIZE)&& LOWER_BOUND+(8*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-7)]+=1;
} else if (numbers[i]<=LOWER_BOUND+(9*BIN_SIZE)&& LOWER_BOUND+(9*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-8)]+=1;
} else if (numbers[i]<=LOWER_BOUND+(10*BIN_SIZE)&& LOWER_BOUND+(10*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-9)]+=1;
}
}
return histogram;
}
public static int findBin( double num ) {
int result=(int) (num/10);
return result;
}
public static String toString( int [] histogram ) {
StringBuilder sb=new StringBuilder();
int BIN_SIZE=(int) ((UPPER_BOUND-LOWER_BOUND)/NUM_BINS);
int temp=(int) ((UPPER_BOUND-LOWER_BOUND)/NUM_BINS);
int tem=(int) LOWER_BOUND;
for(int i=0;i"["+tem+".."+BIN_SIZE+"]: "+" ");
for(int j=0;j'*');
}
sb.append( System.getProperty("line.separator") );
tem=BIN_SIZE;
BIN_SIZE+=temp;
}
return sb.toString();
}
public static boolean validInput( double num ) {
if(numUPPER_BOUND) {
return false;
}
return true;
}
public static double[] inputNumbers( Scanner scan ) {
double[] input=new double[MAX_NUMBERS];
int i=0;
while(idouble num=scan.nextDouble();
if(num!=SENTINAL) {
if(validInput(num)) {
input[i]=num;
i++;
}
}
else {
break;
}
}
return input;
}
}
这一串代码在输出的数组不足20个的时候也会自动补全,如何修改从而只显示输入的数组个数的星号.
这个是我的代码运行的
这个是要实现的效果,不需要补全没有到达20的数组.
用代码块功能插入代码，请勿粘贴截图
那你需要有个变量记录数组中实际有效的元素数量才行。不能按数组的大小来计算啊
如下，增加一个有效数据数量的变量NUMS
然后在图表统计函数中，将for循环修改如下：
for (int i = 0; i < numbers.length; i++) {
改为
for (int i = 0; i < NUMS; i++) {
import java.util.Scanner;
public class Histogram{
private static final int SENTINAL = -999; // sentinal value to signal endo of input
private static final int MAX_NUMBERS = 20; // maximum number of numbers to input
private static final double UPPER_BOUND = 100.0; // largest numbers accepted as data
private static final double LOWER_BOUND = 0.0; // smallest numbers accepted as adata
private static final int NUM_BINS = 10; // number of bins in range [0..100]
private static final int NUMS = 0;
private static final int BIN_SIZE = 100/NUM_BINS; // size of each bin
/*
* Method to show an example of using StringBuilder.
*
* You will also notice that this method is called from the
* main function.
*
*/
public static String getHeaderAsString( String me ) {
// Create an instance of the StringBuilder class
// which allows us to create an object of
// a series of strings that can then be converted
// into one large string via the toString method.
//
StringBuilder sb=new StringBuilder();
sb.append( System.getProperty("line.separator") );
sb.append( "Welcome to the Histogram Program " + me + "!" );
me = getFirstName(me);
sb.append( System.getProperty("line.separator") );
sb.append( System.getProperty("line.separator") );
sb.append( "This program will print out a histogram of the numbers" );
sb.append( System.getProperty("line.separator") );
sb.append( "input by you " + getFirstName(me) + "." );
sb.append( System.getProperty("line.separator") );
sb.append( System.getProperty("line.separator") );
sb.append( "Please enter up to " + MAX_NUMBERS + " doubles or " + SENTINAL + " to stop input!" );
sb.append( System.getProperty("line.separator") );
return sb.toString();
}
/*
* Method to return the first name of the user in case
* the full name was entered.
*/
public static String getFirstName(String name ) {
// Note that add the " " to string to be sure
// there is something to split
return (name+" ").split(" ")[0];
}
/*
* local main test driver
*
*/
public static void main(String[] args) {
// Connect to the keyboard as the input stream
Scanner userInput = new Scanner( System.in );
System.out.print( "And who am I working with today? " );
String user = userInput.nextLine();
String heading = getHeaderAsString( user );
// Print out welcome message
System.out.println( heading );
// Call the method which prompts the user
// to input the numbers that will be used
// to build the histogram.
double[] numbers = inputNumbers( userInput );
// Call the method to reate the array histogram
int[] histogram = calculateHistogram( numbers );
// Print the historgram
System.out.println( toString( histogram ) );
}
public static int[] calculateHistogram(double []numbers){
int histogram[] = new int[NUM_BINS];
//looping through numbers array
for (int i = 0; i < NUMS; i++) {
//incrementing the appropriate bins counter based on value
if (numbers[i]<=LOWER_BOUND+BIN_SIZE&& LOWER_BOUND+BIN_SIZE<UPPER_BOUND) {
histogram[NUM_BINS-NUM_BINS]+=1;
}else if (numbers[i]<=LOWER_BOUND+(2*BIN_SIZE)&& LOWER_BOUND+(2*BIN_SIZE)<=UPPER_BOUND){
histogram[NUM_BINS-(NUM_BINS-1)]+=1;
}else if (numbers[i]<=LOWER_BOUND+(3*BIN_SIZE)&& LOWER_BOUND+(3*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-2)]+=1;
}else if (numbers[i]<=LOWER_BOUND+(4*BIN_SIZE)&& LOWER_BOUND+(4*BIN_SIZE)<=UPPER_BOUND){
histogram[NUM_BINS-(NUM_BINS-3)]+=1;
}else if (numbers[i]<=LOWER_BOUND+(5*BIN_SIZE)&& LOWER_BOUND+(5*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-4)]+=1;
} else if (numbers[i]<=LOWER_BOUND+(6*BIN_SIZE)&& LOWER_BOUND+(6*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-5)]+=1;
} else if (numbers[i]<=LOWER_BOUND+(7*BIN_SIZE)&& LOWER_BOUND+(7*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-6)]+=1;
} else if (numbers[i]<=LOWER_BOUND+(8*BIN_SIZE)&& LOWER_BOUND+(8*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-7)]+=1;
} else if (numbers[i]<=LOWER_BOUND+(9*BIN_SIZE)&& LOWER_BOUND+(9*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-8)]+=1;
} else if (numbers[i]<=LOWER_BOUND+(10*BIN_SIZE)&& LOWER_BOUND+(10*BIN_SIZE)<=UPPER_BOUND) {
histogram[NUM_BINS-(NUM_BINS-9)]+=1;
}
}
return histogram;
}
public static int findBin( double num ) {
int result=(int) (num/10);
return result;
}
public static String toString( int [] histogram ) {
StringBuilder sb=new StringBuilder();
int BIN_SIZE=(int) ((UPPER_BOUND-LOWER_BOUND)/NUM_BINS);
int temp=(int) ((UPPER_BOUND-LOWER_BOUND)/NUM_BINS);
int tem=(int) LOWER_BOUND;
for(int i=0;i<histogram.length;i++) {
sb.append("["+tem+".."+BIN_SIZE+"]: "+" ");
for(int j=0;j<histogram[i];j++) {
sb.append('*');
}
sb.append( System.getProperty("line.separator") );
tem=BIN_SIZE;
BIN_SIZE+=temp;
}
return sb.toString();
}
public static boolean validInput( double num ) {
if(num<LOWER_BOUND|| num>UPPER_BOUND) {
return false;
}
return true;
}
public static double[] inputNumbers( Scanner scan ) {
double[] input=new double[MAX_NUMBERS];
while(NUMS<MAX_NUMBERS) {
double num=scan.nextDouble();
if(num!=SENTINAL) {
if(validInput(num)) {
input[i]=num;
NUMS++;
}
}
else {
break;
}
}
return input;
}
}
package com.example.demo.csdn;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
public class Histogram {
private static final int SENTINAL = -999; // sentinal value to signal endo of input
private static final int MAX_NUMBERS = 20; // maximum number of numbers to input
private static final double UPPER_BOUND = 100.0; // largest numbers accepted as data
private static final double LOWER_BOUND = 0.0; // smallest numbers accepted as adata
private static final int NUM_BINS = 10; // number of bins in range [0..100]
private static final int BIN_SIZE = 100 / NUM_BINS; // size of each bin
/*
* Method to show an example of using StringBuilder.
*
* You will also notice that this method is called from the
* main function.
*
*/
public static String getHeaderAsString(String me) {
// Create an instance of the StringBuilder class
// which allows us to create an object of
// a series of strings that can then be converted
// into one large string via the toString method.
//
StringBuilder sb = new StringBuilder();
sb.append(System.getProperty("line.separator"));
sb.append("Welcome to the Histogram Program " + me + "!");
me = getFirstName(me);
sb.append(System.getProperty("line.separator"));
sb.append(System.getProperty("line.separator"));
sb.append("This program will print out a histogram of the numbers");
sb.append(System.getProperty("line.separator"));
sb.append("input by you " + getFirstName(me) + ".");
sb.append(System.getProperty("line.separator"));
sb.append(System.getProperty("line.separator"));
sb.append("Please enter up to " + MAX_NUMBERS + " doubles or " + SENTINAL + " to stop input!");
sb.append(System.getProperty("line.separator"));
return sb.toString();
}
/*
* Method to return the first name of the user in case
* the full name was entered.
*/
public static String getFirstName(String name) {
// Note that add the " " to string to be sure
// there is something to split
return (name + " ").split(" ")[0];
}
/*
* local main test driver
*
*/
public static void main(String[] args) {
// Connect to the keyboard as the input stream
Scanner userInput = new Scanner(System.in);
System.out.print("And who am I working with today? ");
String user = userInput.nextLine();
String heading = getHeaderAsString(user);
// Print out welcome message
System.out.println(heading);
// Call the method which prompts the user
// to input the numbers that will be used
// to build the histogram.
double[] numbers = inputNumbers(userInput);
// Call the method to reate the array histogram
List<Category> categories = Category.build();
for (double item : numbers) {
categories.stream().filter(category -> category.add(item)).findAny().orElse(null);
}
// Print the historgram
categories.stream().forEach(System.out::println);
}
public static int findBin(double num) {
int result = (int) (num / 10);
return result;
}
public static String toString(int[] histogram) {
StringBuilder sb = new StringBuilder();
int BIN_SIZE = (int) ((UPPER_BOUND - LOWER_BOUND) / NUM_BINS);
int temp = (int) ((UPPER_BOUND - LOWER_BOUND) / NUM_BINS);
int tem = (int) LOWER_BOUND;
for (int i = 0; i < histogram.length; i++) {
sb.append("[" + tem + ".." + BIN_SIZE + "]: " + " ");
for (int j = 0; j < histogram[i]; j++) {
sb.append('*');
}
sb.append(System.getProperty("line.separator"));
tem = BIN_SIZE;
BIN_SIZE += temp;
}
return sb.toString();
}
public static boolean validInput(double num) {
if (num < LOWER_BOUND || num > UPPER_BOUND) {
return false;
}
return true;
}
public static double[] inputNumbers(Scanner scan) {
double[] input = new double[MAX_NUMBERS];
int i = 0;
while (i < MAX_NUMBERS) {
double num = scan.nextDouble();
if (num != SENTINAL) {
if (validInput(num)) {
input[i] = num;
i++;
}
} else {
break;
}
}
return input;
}
static class Category {
private Double begin;
private boolean beginInclude;
private Double end;
private List<Double> data;
public static List<Category> build() {
return IntStream.rangeClosed(0, 100 / 10 - 1).mapToObj(item -> new Category(item * 10d, item == 0 ? true : false, (item + 1) * 10d)).collect(Collectors.toList());
}
public boolean add(Double param) {
boolean result = false;
if (begin == param && beginInclude) {
result = true;
data.add(param);
} else if (begin < param && param <= end) {
result = true;
data.add(param);
}
return result;
}
@Override
public String toString() {
return new StringBuilder().append(this.beginInclude ? "[" : "(").append(begin).append("...").append(end).append("]:").append(data.isEmpty() ? "" : IntStream.rangeClosed(0, data.size() - 1).mapToObj(item -> "*").collect(Collectors.joining())).toString();
}
public Category(Double begin, boolean beginInclude, Double end) {
this.begin = begin;
this.beginInclude = beginInclude;
this.end = end;
this.data = new ArrayList<>();
}
public double getBegin() {
return begin;
}
public void setBegin(Double begin) {
this.begin = begin;
}
public boolean isBeginInclude() {
return beginInclude;
}
public void setBeginInclude(boolean beginInclude) {
this.beginInclude = beginInclude;
}
public double getEnd() {
return end;
}
public void setEnd(Double end) {
this.end = end;
}
}
}
- 这篇文章：Java常量与静态常量能不能修改值 也许有你想要的答案，你可以看看
如果你已经解决了该问题, 非常希望你能够分享一下解决方案, 写成博客, 将相关链接放在评论区, 以帮助更多的人 ^-^