我對(duì) Java 完全是菜鳥，但我希望制作一個(gè)程序，接受用戶的輸入，[A/a] - [C/c]、[D/d] - [F/f] 等等，然后返回一個(gè)值（[A/aC/c = 1], [D/dF/f = 2]....如果輸入不是 AZ 或 az，則返回“無效輸入”。（我想我自己可以解決這個(gè)問題）。我想我可以在輸入上做一個(gè)“ToUpperCase”語句，但我不完全確定如何這樣做。我不想使用任何特殊的數(shù)據(jù)庫。到目前為止，這是我的代碼：導(dǎo)入java.util.Scanner；公共課 TelefonTastatur {public static void main(String[] args) { String korrTall = "Korresponderer til tallet "; //Strings are in Norwegian, but I don't need help with those :-) System.out.println("Dette programmet konverterer bokstav-input til korresponderende tall p? et telefontastatur."); System.out.println("Oppgi en bokstav (A-Z: "); //Asks user for A-Z input. Scanner sc = new Scanner(System.in); char c = sc.next().charAt(0); //Perhaps toUpperCase to lower number of switch cases? switch (c) { case ('A'-'C'): //Not sure how to make A-C and/or a-c. I could make an individual case for all inputs, but that would make a lot of code. case ('a'-'c'): System.out.print(korrTall + "2."); break; case (D/d - F/f): case (): System.out.print(korrTall + "3."); break; case (G/g - I/i): case (): System.out.print(korrTall + "4."); break; case (J/j - L/l): case (): System.out.print(korrTall + "5."); break; case (M/m - O/o): case (): System.out.print(korrTall + "6."); break; case (P/p - S/s): case (): System.out.print(korrTall + "7."); break; case (T/t - V/v): case (): System.out.print(korrTall + "8."); break; case (W/w - Z/z): case (): System.out.print(korrTall + "9."); break; case 'F': case 'f': System.out.print(korrTall + "0."); break; default: System.out.println("Det du har tastet inn tilsvarer ikke noe tall p? et telefontastatur."); break; }}}
3 回答
有只小跳蛙
TA貢獻(xiàn)1824條經(jīng)驗(yàn) 獲得超8個(gè)贊
如果您想讀取用戶的一封信，您可以使用readInput()代碼片段中提供的內(nèi)容。
然后，例如在您的 中main()，您可以要求用戶輸入 2 個(gè)字母，然后您將向他提供結(jié)果。
public static void main(String[] args) {
try{
char inputOne = readInput();
char inputTwo = readInput();
handle(inputOne,inputTwo);
}catch(Exception e){
System.out.println(e.getMessage());
}
}
static char readInput(){
System.out.println("Insert a character");
String input = Console.readLine();
if (input.length==0) {
char c = input.charAt(0);
if (Character.isLetter(c)) {
return c;
}
}
throw new Exception("Invalid input!");
}
static void handle(char a, char b){
// your logic to handle the input of the user
}
慕容森
TA貢獻(xiàn)1853條經(jīng)驗(yàn) 獲得超18個(gè)贊
您將必須使用 Scanner 類來完成用戶輸入。
import java.util.Scanner;
然后創(chuàng)建一個(gè)接受鍵盤輸入的變量。
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter a letter: ");
String text = keyboard.nextLine();
創(chuàng)建一個(gè)方法，返回給定字符的數(shù)字。 在Java中a-z等于，并且等于.97-122A-Z65-90
public int toNum(String text) {
//Ensure that the text is only 1 character long.
if(text.length() > 1) return -1;
//Convert the one-character String to type char.
char letter = text.charAt(0);
//Convert char to its equivalent number value.
int rawNum = letter;
int newNum;
//Convert the number to a value 0-25.
if(rawNum >= 'a' && rawNum <= 'z') {
newNum = rawNum - 'a';
} else if(rawNum >= 'A' && rawNum <= 'Z') {
newNum = rawNum - 'A';
} else {
//None of the characters were letters A-Z.
System.out.println("Invalid input");
return -1;
}
//If {a,b,c} are 1 and {d,e,f} are 2, then {0,1,2} -> 1 and {3,4,5} -> 2
//Take the floor of the new number divided by 3.
int toReturn = Math.floor(newNum / 3.0) + 1;
return toReturn;
}
現(xiàn)在只需使用用戶輸入調(diào)用您的方法即可。
toNum(text);
您也可以打印用戶輸入的返回值。
System.out.println(toNum(text));
慕工程0101907
TA貢獻(xiàn)1887條經(jīng)驗(yàn) 獲得超5個(gè)贊
你的問題根本不清楚，但我盡力幫助你。下次發(fā)布你嘗試過的內(nèi)容。
這個(gè)簡單的代碼會(huì)對(duì)您有所幫助，這可以改進(jìn)，所以讓我們這樣做：D
Scanner scanner = new Scanner(System.in);
System.out.println("Insert first char");
String firstChar = scanner.next().toUpperCase();
if (firstChar.length() != 1 || (firstChar.toCharArray()[0] < 65 || firstChar.toCharArray()[0] > 90)) {
System.out.println("Please, insert one single character [a-z/A-Z]");
return;
}
System.out.println("Insert second char");
String secondChar = scanner.next().toUpperCase();
if (secondChar.length() != 1 || (secondChar.toCharArray()[0] < 65 || firstChar.toCharArray()[0] > 90)) {
System.out.println("Please, insert one single character");
return;
}
System.out.println(firstChar + " - " + secondChar + " = " + Math.abs(firstChar.toCharArray()[0] - secondChar.toCharArray()[0]));
請注意，您可以創(chuàng)建方法來執(zhí)行重復(fù)操作。在這個(gè)簡單的示例中，您可以創(chuàng)建一個(gè)方法來檢查您剛剛從鍵盤讀取的內(nèi)容是否是單個(gè)字符。
您可以做的另一項(xiàng)改進(jìn)是處理用戶插入錯(cuò)誤的內(nèi)容。
讓我們嘗試編碼：D 再見
添加回答
舉報(bào)
0/150
提交
取消