Java字符串比较方法。
JavaString类提供了不同的比较方法，即：
该compareTo()方法
此方法按字典顺序比较两个字符串。如果当前String对象在字典上在参数字符串之前，则此方法返回一个负整数。一个正整数，如果当前的String对象在字典上遵循该参数当字符串相等时为true。
示例
import java.lang.*;
public class StringDemo {
public static void main(String[] args) {
String str1 = "tutorials", str2 = "point";
//比较str1和str2-
int retval = str1.compareTo(str2);
//打印比较的返回值
if (retval < 0) {
System.out.println("str1 is greater than str2");
}
else if (retval == 0) {
System.out.println("str1 is equal to str2");
} else {
System.out.println("str1 is less than str2");
}
}
}输出结果
str1 is less than str2
该compareToIgnoreCase()方法
此方法与compareTo()方法相同，它按字典顺序比较两个字符串，忽略大小写差异。
示例
import java.lang.*;
public class StringDemo {
public static void main(String[] args) {
String str1 = "tutorials", str2 = "TUTORIALS";
//比较str1和str2- with case ignored
int retval = str1.compareToIgnoreCase(str2);
//打印比较的返回值
if (retval > 0) {
System.out.println("str1 is greater than str2");
}
else if (retval == 0) {
System.out.println("str1 is equal to str2");
} else {
System.out.println("str1 is less than str2");
}
}
}输出结果
str1 is equal to str2
该equals()方法
此方法将此字符串与指定对象进行比较。当且仅当参数不为null并且是一个String对象，表示与此对象相同的字符序列时，结果为true。
示例
import java.lang.*;
public class StringDemo {
public static void main(String[] args) {
String str1 = "sachin tendulkar";
String str2 = "amrood admin";
String str3 = "amrood admin";
//检查是否相等
boolean retval1 = str2.equals(str1);
boolean retval2 = str2.equals(str3);
//打印返回值
System.out.println("str2 is equal to str1 = " + retval1);
System.out.println("str2 is equal to str3 = " + retval2);
}
}输出结果
str2 is equal to str1 = false str2 is equal to str3 = true
该equalsIgnoreCase()方法
此方法与该ignoreCase()方法相同，不同之处在于，如果两个字符串的长度相同，并且两个字符串中的对应字符相等，则忽略大小写，则忽略两个字符串。
示例
import java.lang.*;
public class StringDemo {
public static void main(String[] args) {
String str1 = "sachin tendulkar";
String str2 = "amrood admin";
String str3 = "AMROOD ADMIN";
//检查是否相等 with case ignored
boolean retval1 = str2.equalsIgnoreCase(str1);
boolean retval2 = str2.equalsIgnoreCase(str3);
//打印返回值
System.out.println("str2 is equal to str1 = " + retval1);
System.out.println("str2 is equal to str3 = " + retval2);
}
}输出结果
str2 is equal to str1 = false str2 is equal to str3 = true