//JAVA PROGRAMMING Ok so can someone explain to me why the first one will equal
ID: 673941 • Letter: #
Question
//JAVA PROGRAMMING
Ok so can someone explain to me why the first one will equal 7 and the second one will equal -7 and the last 0? I don't understand why the number is 7 and -7. Where does this come from?
public class Comparisons {
public static void main(String[] args) {
// TODO Auto-generated method stub
String s1 ="Welcome to Java";
String s2 = "Programming is fun";
String s3 = "Welcome to Java";
System.out.println(s1.compareTo(s2));
System.out.println(s2.compareTo(s3));
System.out.println(s2.compareTo(s2));
}
}
output
7
-7
0
Explanation / Answer
Open Declaration int java.lang.String.compareTo(String anotherString)
compareTo
public int compareTo(String anotherString)
Compares two strings lexicographically. The comparison is based on the Unicode value of each character in the strings. The character sequence represented by this String object is compared lexicographically to the character sequence represented by the argument string. The result is a negative integer if this String object lexicographically precedes the argument string. The result is a positive integer if this String object lexicographically follows the argument string. The result is zero if the strings are equal; compareTo returns 0 exactly when the equals(Object) method would return true.
This is the definition of lexicographic ordering. If two strings are different, then either they have different characters at some index that is a valid index for both strings, or their lengths are different, or both. If they have different characters at one or more index positions, let k be the smallest such index; then the string whose character at position k has the smaller value, as determined by using the < operator, lexicographically precedes the other string. In this case, compareTo returns the difference of the two character values at position k in the two string -- that is, the value:
this.charAt(k)-anotherString.charAt(k)
If there is no index position at which they differ, then the shorter string lexicographically precedes the longer string. In this case, compareTo returns the difference of the lengths of the strings -- that is, the value:
this.length()-anotherString.length()
Specified by:compareTo in interface Comparable<String>Parameters:anotherString - the String to be compared.Returns:the value 0 if the argument string is equal to this string; a value less than 0 if this string is lexicographically less than the string argument; and a value greater than 0 if this string is lexicographically greater than the string argument.
Here we have W-P i.e. 23 - 16 = 7
and P - W i.e. 16-23 = -7
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.