java的输入语句小结

Java中做输入的方式:通过控制台输入数据,需要使用Scanner对象来操作,那么java输入语句到底有哪些呢?下面跟yjbys小编一起来看看吧!

java的输入语句小结

  1.使用Scanner

使用时需要引入包import ner;首先定义Scanner对象

Scanner sc = new Scanner();

如果要输入整数,则 int n = Int();

String类型的,则String temp = ();

比如:

import ner;

public class Test {

public static void main(String[] args) {

Scanner scanner = new Scanner();

int[] days = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

int month = -1;

while(true) {

try {

t("请输入月份:");

month = Int();

if(month >= 1 && month <= 12) {

break;

}

tln("** 请输入正确的.月份 **");

} catch (Exception e) {

tln("** 格式错误!请输入数字 **");

();

}

}

tln(month + " 月份有:" + days[month - 1] + " 天");

}

}

  2.使用BufferedReader

用前需要引入 import er;

BufferedReader br = new BufferedReader( new InputStreamReader() );

String input = Line();

比如:

==================================================================================================

import .*;

public class importtext {

public static void main(String[] args) {

String st;

int num;

float fnum;

try{

t("输入:");

BufferedReader br=new BufferedReader(new InputStreamReader());

st = Line();

t("输入一个数:");

num = eInt(Line());

t("输入一个浮点数:");

fnum = eFloat(Line());

t("输出:"+st+'n');

t("输出:"+num+'n');

t("输出:"+fnum+'n');

}catch(IOException e){}

}

}

==================================================================================================

package com.s2;

import .*;

public class Input

{

public static void main(String[] args)throws IOException

{

while(true)

{

BufferedReader buf;

String str;

buf =new BufferedReader(new InputStreamReader());

tln("Input a string:");

str=Line();

tln("String="+str);

}

}

}

==================================================================================================

应该注意的是:Java把从键盘输入的数据一律看作是字符串,因此若要从键盘输入并让系统认可是数值型数据,必须经过转换。

比如:

package com.s2;

import .*;

public class Input

{

public static void main(String[] args)throws IOException

{

while(true)

{

int num;

BufferedReader buf;

String str;

buf =new BufferedReader(new InputStreamReader());

tln("Input an integer:");

str=Line();

num=eInt(str);

tln("String="+str);

tln("Integer="+str);

}

}

}