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只要你教我，我就可以學習。我只是在談論Java，因爲它是我學習的最佳方式。如果你發現任何你認爲我可以在代碼中改進的東西，我很樂意聽到它。不知道發生了什麼 - 沒有錯誤（Java新手）
我爲自己準備的項目的總體目標是用Java創建一個存儲有關人員信息的程序。然後將該信息傳輸到Tomcat服務器，我將設置運行SQL。
現在你明白我的總體目標（我是從它很遠），我的問題是：
我可以去詢問我一個條目的命令和名稱等代碼的一部分沒問題。但是，當我輸入「read」並按下回車鍵時，它似乎跳過else語句，我已經設置並直接進入else部分。
編輯：我更新了帖子，以顯示什麼解決了問題。
工作代碼：
import javax.print.DocFlavor.READER;
import java.util.ArrayList;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner reader = new Scanner(System.in);
int total = 0;
int years = 0;
int invested =0;
ArrayList<String> names = new ArrayList<String>(0);
ArrayList<String> address = new ArrayList<String>(0);
ArrayList<String> ids = new ArrayList<String>(0);
Scanner sReader = new Scanner(System.in);
while(reader.nextLine().toLowerCase().split(" ")[0] != "exit")
{
System.out.print("Enter Instruction: ");
String n = reader.nextLine();
String[] uin = n.toLowerCase().split(" ");
if(uin[0].equals("add"))
{
try {
System.out.println(add(Integer.parseInt(uin[1]),Integer.parseInt(uin[2])));
} catch (NumberFormatException e) {
System.out.println("Numbers Only");
System.out.print(e.getMessage());
} catch (Exception e){
System.out.println("ERROR");
}
}
if(uin[0].equals("sub") || uin[0].equals("subtract"))
{
try {
System.out.print(Integer.parseInt(uin[1])-Integer.parseInt(uin[2]));
} catch (NumberFormatException e){
System.out.println("Numbers Only");
System.out.print(e.getMessage());
} catch (Exception e){
System.out.println("ERROR");
}
}
if(uin[0].equals("string"))
{
String string = "this is a string.";
System.out.println(string.indexOf("cat"));
}
if(uin[0].equals("a"))
{
total+=Integer.parseInt(uin[1]);
invested+=Integer.parseInt(uin[1]);
}
if(uin[0].equals("aa"))
{
total+=10000;
invested+=10000;
}
if(uin[0].equals("bb"))
{
total-=55000;
invested-=55000;
}
if(uin[0].equals("aq"))
{
for(int i = 0;i < Integer.parseInt(uin[1]);i++){
total+=10000;
invested+=10000;
total*=1.06;
years+=1;
}
years-=1;
}
if(uin[0].equals("exit"))
{
break;
}
if(uin[0].equals("entry")){
for(int i=0;i==0;i+=0){
System.out.print("Entry Command: ");
String input = sReader.nextLine();
if(input.equals("exit")){
i = 1;
}else if(input.equals("read")){
for(int y=0;y<names.size();y++){
System.out.println("User #"+y);
System.out.println(names.get(y).toString());
System.out.println(address.get(y).toString());
System.out.println(ids.get(y).toString());
}
}else{
System.out.print("Name: ");
input = sReader.nextLine();
names.add(input);
System.out.print("Address: ");
input = sReader.nextLine();
address.add(input);
System.out.print("ID: ");
input = sReader.nextLine();
ids.add(input);
}
}
}
total*=1.06;
years+=1;
double earn = Math.floor(total) * 0.06;
System.out.println("Bank: " + total);
System.out.println("Invested: " + invested);
System.out.println("Yearly Earnings: " + earn);
System.out.println("Years: " + years);
}
}
public static int add(int n1, int n2){
int out;
try{
out = (n1+n2);
return(out);
}catch (Exception e){
System.out.print("ERROR");
return(0);
}
}
}
舊代碼：
import javax.print.DocFlavor.READER;
import java.util.ArrayList;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner reader = new Scanner(System.in);
int total = 0;
int years = 0;
int invested =0;
ArrayList<String> names = new ArrayList<String>(0);
ArrayList<String> address = new ArrayList<String>(0);
ArrayList<String> ids = new ArrayList<String>(0);
Scanner sReader = new Scanner(System.in);
while(reader.nextLine().toLowerCase().split(" ")[0] != "exit")
{
System.out.print("Enter Instruction: ");
String n = reader.nextLine();
String[] uin = n.toLowerCase().split(" ");
if(uin[0].equals("add"))
{
try {
System.out.println(add(Integer.parseInt(uin[1]),Integer.parseInt(uin[2])));
} catch (NumberFormatException e) {
System.out.println("Numbers Only");
System.out.print(e.getMessage());
} catch (Exception e){
System.out.println("ERROR");
}
}
if(uin[0].equals("sub") || uin[0].equals("subtract"))
{
try {
System.out.print(Integer.parseInt(uin[1])-Integer.parseInt(uin[2]));
} catch (NumberFormatException e){
System.out.println("Numbers Only");
System.out.print(e.getMessage());
} catch (Exception e){
System.out.println("ERROR");
}
}
if(uin[0].equals("string"))
{
String string = "this is a string.";
System.out.println(string.indexOf("cat"));
}
if(uin[0].equals("a"))
{
total+=Integer.parseInt(uin[1]);
invested+=Integer.parseInt(uin[1]);
}
if(uin[0].equals("aa"))
{
total+=10000;
invested+=10000;
}
if(uin[0].equals("bb"))
{
total-=55000;
invested-=55000;
}
if(uin[0].equals("aq"))
{
for(int i = 0;i < Integer.parseInt(uin[1]);i++){
total+=10000;
invested+=10000;
total*=1.06;
years+=1;
}
years-=1;
}
if(uin[0].equals("exit"))
{
break;
}
if(uin[0].equals("entry")){
for(int i=0;i==0;i+=0){
System.out.print("Entry Command: ");
sReader = new Scanner(System.in);
System.out.println(sReader.nextLine());
if(sReader.nextLine().equals("exit")){
i = 1;
}else if(sReader.nextLine().equals("read")){
System.out.println(names.size());
System.out.println("yup");
for(int y=0;y==names.size()-1;y++){
System.out.println(names);
System.out.println(names.get(y));
System.out.println(address.get(y));
System.out.println(ids.get(y));
}
}else{
System.out.print("Name: ");
sReader = new Scanner(System.in);
names.add(sReader.nextLine());
System.out.print("Address: ");
sReader = new Scanner(System.in);
address.add(sReader.nextLine());
System.out.print("ID: ");
sReader = new Scanner(System.in);
ids.add(sReader.nextLine());
}
}
}
total*=1.06;
years+=1;
double earn = Math.floor(total) * 0.06;
System.out.println("Bank: " + total);
System.out.println("Invested: " + invested);
System.out.println("Yearly Earnings: " + earn);
System.out.println("Years: " + years);
}
}
public static int add(int n1, int n2){
int out;
try{
out = (n1+n2);
return(out);
}catch (Exception e){
System.out.print("ERROR");
return(0);
}
}
}
你繼續閱讀文本的每次調用'sReader.nextLine時間（）新行'。將結果存儲在變量中，並在您的條件中使用該變量。 –
歡迎來到堆棧溢出！它看起來像你需要學習使用調試器。請幫助一些[互補調試技術]（https://ericlippert.com/2014/03/05/how-to-debug-small-programs/）。如果您之後仍然有問題，請隨時返回更多詳情。 –
你for for循環看起來很奇怪...'for（int y = 0; y == names.size（） - 1; y ++）{'可能不會輸入 –