介紹：
簡單來說，Scanner就是用來獲取用戶在控制臺輸入的字符串，也可以獲取一個文件中的字符串。
（推薦教程：java入門教程）
java.util.Scanner 是 Java5 的特征，一個可以使用正則表達式來解析基本類型和字符串的簡單文本掃描器。
使用方法介紹：
1、使用不同的 next 方法將得到的標記轉(zhuǎn)換為不同類型的值，比如說要從獲控制臺取一個輸入字符串中的int類型的數(shù)字，使用nextInt。
代碼示例：
Scanner sc = new Scanner(System.in); int i = sc.nextInt();
如果需要從一個名文為numbers件中去獲取long 類型的數(shù)字。
Scanner sc = new Scanner(new File("numbers"));
while (sc.hasNextLong()) {
long longNumber = sc.nextLong();
}（視頻教程推薦：java視頻教程）
2、從帶有空格中的字符串中獲取指定的內(nèi)容
比如刪去字符串 ： 1 fish 2 fish red fish blue fish 中的 fish和空格。
代碼示例：
String input = "1 fish 2 fish red fish blue fish";
// 使用正則匹配的方式獲取想要的內(nèi)容
Scanner s = new Scanner(input).useDelimiter("\\s*fish\\s*");
System.out.println(s.nextInt());
System.out.println(s.nextInt());
System.out.println(s.next());
System.out.println(s.next());
// 打開文件之后切記要關(guān)閉
s.close();完整代碼示例：
public static void main( String[] args )
{
if(args!=null){
println("命令行參數(shù)：");
for(String s:args){
println(s);
}
}
Scanner input = new Scanner(System.in);
print( "input x exist。" );
String str = null ;
do{
println("");
print(":");
str = input.next();
System.out.println("您輸入的是："+str);
}while(!"x".equalsIgnoreCase(str));
System.out.println("你輸入了\"x\"，程序已經(jīng)退出！");
input.close(); // 關(guān)閉資源
}
public static void println(String msg){
System.out.println( msg );
}
public static void print(String msg){
System.out.print( msg );
}The above is the detailed content of What is the function of Scanner class in Java. For more information, please follow other related articles on the PHP Chinese website!
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