我試圖在地址中輸入錯誤的內容以重復“您住在哪里？”的問題 使用 while 方法，但它似乎不再起作用了。import java.util.Scanner;public class ImScrewed { public static void main(String[] args) { boolean flag = true; Scanner scan = new Scanner(System.in); while (flag) { System.out.println("== Welcome to UwU Cafe! =="); System.out.print("What is your name? [Starts with 'Mr. ' or 'Ms. '] : "); String name = scan.nextLine(); if (name.startsWith("Ms. ") || name.startsWith("Mr. ")) { System.out.println("Welcome : " + name); flag = false; } else { System.out.println("Please re-enter your name"); } } System.out.println("Where do you live? [Contains 'Street']"); String address = scan.nextLine(); if (address.contains("Street")) { System.out.println("Proceed to the next step"); flag = false; } else { System.out.println("Please re-enter your address"); } }}
1 回答
繁花不似錦
TA貢獻1851條經驗 獲得超4個贊
如果出現錯誤，您需要循環返回。在布爾變量和簡單的 while 循環的幫助下，應該沒問題。
像這樣的東西：
boolean flag = true;
do {
String name = scan.nextLine();
if (name.startsWith("Ms. ") || name.startsWith("Mr. ")) {
System.out.println("Welcome : " + name);
// break the loop.
flag = false;
} else {
System.out.println("Please re-enter your name");
}
} while (flag);
您也可以消除該變量。通過做類似的事情：
while (true) {
String name = scan.nextLine();
if (name.startsWith("Ms. ") || name.startsWith("Mr. ")) {
System.out.println("Welcome : " + name);
break;
} else {
System.out.println("Please re-enter your name");
}
}
編輯：支持或多個字段。
// previous while loop here
flag = true; // resetting flag
while (flag) {
System.out.println("Where do you live? [Contains 'Street']");
String address = scan.nextLine();
if (address.contains("Street")) {
System.out.println("Proceed to the next step");
// terminate the loop
flag = false;
} else {
System.out.println("Please re-enter your address");
}
}
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