简单问题:

[bluemoon98]

怎样取字符串的前两位

[lynx1111]

substring

[lynx1111]

String aa="aasdfsadf";
System.out.println(aa.substring(0,2));

[yaray]

String类:

public String substring(int startPos) // 取开始位置到字符串尾部的字符
如:
String str = "abcdefg";
System.out.println(str.substring(3));// 值是 cdefg

public String substring(int startPos,int endPos)
如:
String str = "abcdefg";
System.out.println(str.substring(3,5));// 值是 cde