字符串索引两个字符串之间的差异

Question

I have two String Lists just like below:

List1 (Generated by sql resultset)

10001
10100
10001

List2 (Generated by sql resultset)

10000
10000
10000

Button Action;

private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        try {
            // TODO add your handling code here:
            createList1();
            createList2();
            difference();
        } catch (Exception ex) {
            Logger.getLogger(GUI.class.getName()).log(Level.SEVERE, null, ex);
        }       
    }    

difference void;

public void difference (){
       int minLen = Math.min(List1.get(0).length(), List2.get(0).length());
        for (int i = -1 ; i != minLen ; i++) {
          char chA = List1.get(0).charAt(i);
          char chB = List2.get(0).charAt(i);
        if (chA != chB) {
        System.out.println(chA);
        }
       }  
    }

I want to find which index numbers are different in List1 for index 0.

Thanks in advance.

Answer 1

Make a loop that iterates the index i from zero the length of the shorter of the two strings, and compare characters one by one, using the == operator:

int minLen = Math.min(a.length(), b.length());
for (int i = 0 ; i != minLen ; i++) {
    char chA = a.charAt(i);
    char chB = b.charAt(i);
    if (chA != chB) {
        ...
    }
}

Before starting the comparison you need to check that a and b are not null . Otherwise, getting the length is going to trigger a null reference exception.

Answer 2

Try this:

public List<Integer> findDiffIndexes(String s1, String s2 ) {
    List<Integer> indexes = new ArrayList<Integer>();
    for( int i = 0; i < s1.length() && i < s2.length(); i++ ) {
        if( s1.charAt(i) != s2.charAt(i) ) {
            indexes.add( i );
        }
    }
    return indexes;
}

Answer 3

Do loop on List 1 and List2, and compare index value like, I assume you that both list has same size so,

for(int i=0;i<list1.size();i++)
{
  if(!list1.get(i).equals(list2.get(i))
   {
     System.out.println("Not equal value of Index="+i);
   }
}

Answer 4

Assuming the two Strings will always be the same length...

String first = "10000";
String second = "10101";

ArrayList differentIndexes = new ArrayList();

for(int i=0; i<first.length(); i++){
if(first.charAt(i)!=second.charAt(i)){
differentIndexes.add(i);
}
}

Answer 5

https://commons.apache.org/proper/commons-lang/javadocs/api-3.1/org/apache/commons/lang3/StringUtils.html#difference%28java.lang.String,%20java.lang.String%29

public static String difference(String str1, String str2)

Compares two Strings, and returns the portion where they differ. (More precisely, return the remainder of the second String, starting from where it's different from the first.)

For example, difference("i am a machine", "i am a robot") -> "robot".

  StringUtils.difference(null, null) = null StringUtils.difference("", "") = "" StringUtils.difference("", "abc") = "abc" StringUtils.difference("abc", "") = "" StringUtils.difference("abc", "abc") = "" StringUtils.difference("ab", "abxyz") = "xyz" StringUtils.difference("abcde", "abxyz") = "xyz" StringUtils.difference("abcde", "xyz") = "xyz" Parameters: str1 - the first String, may be null str2 - the second String, may be null Returns: the portion of str2 where it differs from str1; returns the empty String if they are equal Since: 2.0