下面是我的Java程序。现在,程序正确运行的唯一方法是使最后一列最长。如果数组中的最后一列不是最长的列,则输出不正确。例如,如果food
数组在第二列中的元素比在第三列中的元素多,如下所示:
String[][] food = {
{"Bannana", "Apple", "Pear", "Orange"}, // fruits
{"GreenBean", "Iceburg", "Spenach", "peas", "carrots", "potatoes", "beans"}, // vegetables
{"Steak", "Baccon", "Beef", "TurkeyB", "TurkeyBacon", "Chicken"} // meats
};
然后,例如,如果输入chicken
作为输入,则输出为:
Yo have no favorite food
Your favorite food is Chicken
而且,例如,如果输入为biscuit
,则输出为:
Yo have no favorite food
Yo have no favorite food
那么,有没有办法只打印一次"Yo have no favorite food"
或正确打印出喜欢的食物而不必最后一列最长?
代码如下:
package com.begg;
import java.util.*;
public class List {
static Scanner sc = new Scanner(System.in);
public static void main(String[] args) {
String[][] food = {
{"Bannana", "Apple", "Pear", "Orange"}, // fruits
{"GreenBean", "Iceburg", "Spenach", "peas"}, // vegetables
{"Steak", "Baccon", "Beef", "TurkeyB", "TurkeyBacon", "Chicken"} // meats
};
for(int row = 0; row < food.length; row++) {
for (int col = 0; col < food[row].length; col ++) {
System.out.print(food[row][col] + ", ");
}
System.out.println();
}
System.out.println("Enter your favorite out of the options above:");
String k = sc.next();
loop2:
for(int row2 = 0; row2<food.length; row2++) {
for (int col2 = 0; col2< food[row2].length; col2++) {
if (k.equalsIgnoreCase(food[row2][col2])) {
System.out.println("Your favorite food is " + food[row2][col2]);
break loop2;
}
else if (!(k.equalsIgnoreCase(food[row2][col2])) & col2== 5 ) {
System.out.println("Yo have no favorite food");
}
}
}
}
}
谢谢!
答案 0 :(得分:0)
使用哈希表而不是两个for
来迭代2d array
。像;
import java.util.HashSet;
import java.util.Scanner;
public class List {
static Scanner sc = new Scanner(System.in);
public static void main(String[] args) {
String[][] food = {
{"Bannana", "Apple", "Pear", "Orange"}, // fruits
{"GreenBean", "Iceburg", "Spenach", "peas"}, // vegetables
{"Steak", "Baccon", "Beef", "TurkeyB", "TurkeyBacon", "Chicken"} // meats
/*
* Your longest part of your array should be the longest
* if it's not, using the length of the column to end a loop may cause problems
* if you use the row instead, everything after the row three will execute
*
*/
};
for (int row = 0; row < food.length; row++) {
for (int col = 0; col < food[row].length; col++) {
System.out.print(food[row][col] + ", ");
}
System.out.println();
}
System.out.println("Enter your favorite out of the options above:");
String k = sc.next();
final HashSet<Object> setOfFood = new HashSet<>();
//Add all food to hashset
for (String[] subFoodList : food) {
for (String subFood : subFoodList) {
setOfFood.add(subFood.toLowerCase());
}
}
//if set containts scanners string returns relevant response
if (setOfFood.contains(k.toLowerCase())) {
System.out.println("Your favorite food is " + k);
} else {
System.out.println("Yo have no favorite food");
}
}
}
答案 1 :(得分:0)
更改此部分:
else if (!(k.equalsIgnoreCase(food[row2][col2])) & col2== 5 ) {
System.out.println("Yo have no favorite food");
}
对此:
else if (!(k.equalsIgnoreCase(food[row2][col2])) && row2 == food.length-1 && col2 == food[row2].length-1) {
System.out.println("Yo have no favorite food");
}
应该做我认为您想要的。编辑过的else if
会检查是否已检查数组的所有值(与哪一列更长无关),如果没有匹配的输入,则它将执行一次System.out.println("Yo have no favorite food");
。