JAVA中的字符串的indexOf函数 和substring
int indexOf(int ch,int fromIndex)函数：就是字符ch在字串fromindex位后出现的第一个位置.没有找到返加-1
eg：String str="a2dfcfar1bzvb"; System.out.println(str.indexOf(97,2)); 看这个例子，输出：6 a的ASCII为97，就从d开始找a找到了输出a所在字符串的确切位置，找不到就输出-1！（java中位置第一个从0开始）
String.indexOf函数用法小结
1. indexOf的参数是String, startIndex: Number; 1. indexOf的参数是String, startIndex: Number;
indexOf的返回值为int, indexOf的返回值为int,
2. Function indexOf 包含如下几个格式：
1). Strng.indexOf(substring) //搜索String中的substring,默认从0位开始；
2). String.indexOf(substring, int m) //搜索String中的substring, 默认从第m位开始； 2. Function indexOf 包含如下几个格式： 1). Strng.indexOf(substring) //搜索String中的substring,默认从0位开始； 2). String.indexOf(substring, int m) //搜索String中的substring, 默认从第m位开始；
1). Strng.indexOf(substring) //搜索String中的substring,默认从0位开始；
2). String.indexOf(substring, int m) //搜索String中的substring, 默认从第m位开始； 2. Function indexOf 包含如下几个格式： 1). Strng.indexOf(substring) //搜索String中的substring,默认从0位开始； 2). String.indexOf(substring, int m) //搜索String中的substring, 默认从第m位开始；
public class Hehe
{
int i;
int x;
String ip= null;
String input1 = null;
String input2 = null;
public void main(String args[]){
ip = "126.168.1.1";
i = ip.indexOf(.);
x = ip.indexOf(.,i+1);
input1 = ip.substring(0,i);
input2 = ip.substring(i+1, x);
System.out.println("the input1 is "+input1);
System.out.println("the input2 is "+input2);
} public class Hehe { int i; int x; String ip= null; String input1 = null; String input2 = null; public void main(String args[]){ ip = "126.168.1.1"; i = ip.indexOf(.); x = ip.indexOf(.,i+1); input1 = ip.substring(0,i); input2 = ip.substring(i+1, x); System.out.println("the input1 is "+input1); System.out.println("the input2 is "+input2); }
{
int i;
int x;
String ip= null;
String input1 = null;
String input2 = null;
public void main(String args[]){
ip = "126.168.1.1";
i = ip.indexOf(.);
x = ip.indexOf(.,i+1);
input1 = ip.substring(0,i);
input2 = ip.substring(i+1, x);
System.out.println("the input1 is "+input1);
System.out.println("the input2 is "+input2);
} public class Hehe { int i; int x; String ip= null; String input1 = null; String input2 = null; public void main(String args[]){ ip = "126.168.1.1"; i = ip.indexOf(.); x = ip.indexOf(.,i+1); input1 = ip.substring(0,i); input2 = ip.substring(i+1, x); System.out.println("the input1 is "+input1); System.out.println("the input2 is "+input2); }
} }
结果是 结果是
the input1 is 126
the input2 is 168
the input1 is 126 the input2 is 168
public class Hehe { int i; int x; String ip= null; String input1 = null; String input2 = null; public void main(String args[]){ ip = "126.168.1.1"; i = ip.indexOf(.); x = ip.indexOf(.,i+1); input1 = ip.substring(0,i); input2 = ip.substring(i+1, x); System.out.println("the input1 is "+input1); System.out.println("the input2 is "+input2); } } 结果是 the input1 is 126 the input2 is 168
the input2 is 168
the input1 is 126 the input2 is 168