我試圖將其帶到用戶按下數(shù)字的位置，然后他們輸入他們想要查看的可用選項(xiàng)的字符串。到目前為止，一切正常，除了當(dāng)用戶輸入字符串時，它沒有給出首選輸出.. *顯示電子郵件而不是顏色、用戶 ID 等。這是我的代碼.. 再次感謝！public static void printStuff(Record[] objects) { Scanner in = new Scanner(System.in); System.out.println("Enter the number and record name you would like to see"); int x = in.nextInt(); String bean = in.next(); if (x == 1 || x == 2 || x == 3 || x == 4 || x == 5 && bean.equals("email")) { System.out.println(objects[x].getEmail()); } else if (x == 1 || x == 2 || x == 3 || x == 4 || x == 5 && bean.equals("name")) { System.out.println(objects[x].getfirstName()); } else if (x == 1 || x == 2 || x == 3 || x == 4 || x == 5 && bean.matches("last name")) { System.out.println(objects[x].getlastName()); } else if (x == 1 || x == 2 || x == 3 || x == 4 || x == 5 && bean.matches("balance")) { System.out.println(objects[x].getBalance()); } else if (x == 1 || x == 2 || x == 3 || x == 4 || x == 5 && bean.matches("color")) { System.out.println(objects[x].getColor()); } else if (x == 1 || x == 2 || x == 3 || x == 4 || x == 5 && bean.matches("idnumber")) { System.out.println(objects[x].getnumID()); } }
3 回答
大話西游666
TA貢獻(xiàn)1817條經(jīng)驗(yàn) 獲得超14個贊
嘗試一下，始終避免重新輸入案例并使您的代碼更加高效。
public static void printStuff(Record[] objects) {
Scanner in = new Scanner(System.in);
System.out.println("Enter the number and record name you would like to see");
int x = in.nextInt();
String bean = in.next();
if (x >= 1 && x =< 5 ) {
if (bean.equals("email"))
System.out.println(objects[x].getEmail());
else if (bean.equals("name"))
System.out.println(objects[x].getfirstName());
else if (bean.matches("last name"))
System.out.println(objects[x].getlastName());
else if (bean.matches("balance"))
System.out.println(objects[x].getBalance());
else if (bean.matches("color"))
System.out.println(objects[x].getColor());
else if (bean.matches("idnumber"))
System.out.println(objects[x].getnumID());
}
}
眼眸繁星
TA貢獻(xiàn)1873條經(jīng)驗(yàn) 獲得超9個贊
在所有 if 條件中，&&的優(yōu)先級高于||，因此必須將條件更改為：
(x == 1 || x == 2 || x == 3 || x == 4 || x == 5) && bean.equals("email").
這對應(yīng)于您想要的邏輯，如果x1 到 5 中的某個值 AND bean 等于"email"。但是，請研究比較運(yùn)算符，因?yàn)槟梢詫⑵浜喕癁椋?/p>
(1 <= x && x <= 5) && bean.equals("email").
牧羊人nacy
TA貢獻(xiàn)1862條經(jīng)驗(yàn) 獲得超7個贊
也許更容易閱讀：
if (1 <= x && x <= 5) {
? ? switch (bean) {
? ? ? ? case "email":?
? ? ? ? ? ? System.out.println(record.email);
? ? ? ? ? ? break;
? ? ? ? case "name":?
? ? ? ? ? ? System.out.println(record.firstName);
? ? ? ? ? ? break;
? ? ? ? ...
? ? }
}
使用switch 表達(dá)式(Java 13,?--enable-preview)：
if (1 <= x && x <= 5) {
? ? System.out.println(switch (bean) {
? ? ? ? case "email" -> record.email;
? ? ? ? case "name" -> record.firstName;
? ? ? ? case "last name"-> record.lastName;
? ? ? ? ...
? ? ? ? default -> "unrecognized " + bean;
? ? ? ? // default -> throw new IllegalArgumentException(...);
? ? });
}
或者，如果對未知不執(zhí)行任何操作bean：
if (1 <= x && x <= 5) {
? ? switch (bean) {
? ? ? ? case "email" -> System.out.println(record.email);
? ? ? ? case "name" -> System.out.println(record.firstName);
? ? ? ? ...
? ? }
}
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