Scanner中nextInt（）、nextLine（）方法使用注意事项

一.nextInt()和nextLine()的区别

1.nextInt()方法：Scans the next token of the input as an int. returns：the int scanned from the input nextInt()方法只读取int型数值，剩下的“/n”不会读入，cursor仍然在本行 2.nextLine()方法：This method returns the rest of the current line, excluding any line separator at the end. The position is set to the beginning of the next line. Returns:the line that was skipped nextLine()会读取"\n"，并结束（nextLine() reads till the end of line \n）。

二.代码示例

public class TestLine { public static void main(String[] args) throws FileNotFoundException{ Scanner in = new Scanner(System.in); while(in.hasNext()){ int m = in.nextInt(); String s = in.nextLine(); System.out.println("hello world!"); } } }

String s = in.nextLine();改行代码未被执行，nextInt()只会读取数值，剩下"\n"还没有读取，并将cursor放在本行中。所以，in.nextLine()直接读取“\n”并结束了。

public class TestLine { public static void main(String[] args) throws FileNotFoundException{ Scanner in = new Scanner(System.in); while(in.hasNext()){ int n = in.nextInt(); in.nextLine(); String[] strings = in.nextLine().trim().split(" "); for(String str:strings){ System.out.print(str); } System.out.println(); } } } int n = in.nextInt(); in.nextLine()读取“/n”