The CompareTo in string

In the API source code, the CompareTo of string is actually an ASCII code that compares two strings at a time. If the ASCII equality of two strings continues the subsequent comparison, otherwise the two ASCII difference is returned directly. Returns 0 if two strings are exactly the same. The following is the source code:

 Public intcompareTo (String anotherstring) {intLen1 =count; intLen2 =Anotherstring.count; //gets the shorter length of the two strings    intn =math.min (Len1, len2); CharV1[] =value; CharV2[] =Anotherstring.value; inti =offset; intj =Anotherstring.offset; if(i = =j) {intK =i; intLim = n +i;  while(K <Lim) {CharC1 =V1[k]; CharC2 =V2[k]; //if the two-character ASC is not the same, return directlyif(C1! =C2) {                returnC1-C2; } k++; }    } Else {         while(n--! = 0) {           CharC1 = v1[i++]; CharC2 = v2[j++]; //if the two-character ASC is not the same, return directly           if(C1! =C2) {               returnC1-C2; }        }    }    //if all are the same, return the length of the two string to check    returnLEN1-Len2; }

By the above code, we can easily calculate the value of the CompareTo of two strings:

　　

int i1 = "ABCD". CompareTo ("ADHF");
int i2 = "abc". COMPARETO ("abcdef");
int i3 = "ABCD". CompareTo ("abc");

System.out.println (i1);//-2
System.out.println (I2);-3
SYSTEM.OUT.PRINTLN (i3); 0

Example: Practical application of CompareTo? For simple string sorting. (for example, using CompareTo to sort names)

　　

//use a simple looping order         for(inti = 0; i < array.length-1; i++) {             for(intj = i + 1; J < Array.Length; J + +) {                if(Array[i].compareto (array[j]) > 0) {String temp=Array[i]; Array[i]=Array[j]; ARRAY[J]=temp; }            }        }         for(inti = 0; I < 5; i++) {System.out.println (array[i]); }    }

After sorting the string above, the contents of the strings will be:

James Libai Lilei Owen Wolf

The CompareTo in string