Replace zeros to letter "o" inside words

Question

After ocr recognition I have a lot of words where instead of o I have 0. So I want to replace any zeros inside words.

Up till now I could do only the following

String result ="I don't like th0se books";
result = result.replaceAll("\\w+0\\w*", "o");
System.out.println("RESULT:" + result);

My code returns RESULT:I don't like o books but I need RESULT:I don't like those books. Could anyone say how to do it?

Answer 1

Use a non-word boundary:

result = result.replaceAll("\\B0|0\\B", "o");

That ensures there is at least one word character before or after the 0.

If you want to prevents zero inside a number to be replaced:

result = result.replaceAll("\\b(?!\\d+\\b)(?:0\\B|([^\\W0]+)0)|\\G(?!\\A)0", "$1o");

details:

\\b              # a word boundary
(?!\\d+\\b)      # negative lookahead: not followed by an integer
(?:
    0\\B         # zero and a non-word boundary (means a word character follows)
  |
    ([^\\W0]+)0  # word characters without zero and a zero
)
|
\\G(?!\\A)0  # a zero contiguous to a previous match (not at the start of the string)

(obviously a regex pattern can't make the difference between an isolated "0" and an isolated "o", or between a "0" and a "o" in a reference number, or a number in scientific notation)

---

other way: capturing all the opponents

result = result.replaceAll("((?>(?:[\\W_]+|\\pL+|\\b\\d+\\b)*))(?:\\B0|0\\B)", "$1o");

Answer 2

The regex should be "0" not "\\w+0\\w*".

Also, to keep the rest of the words, use capturing groups: result = result.replaceAll("(\\w+)0(\\w*)", "$1o$2");

To only replace between "letters" and ignoring numbers for the requirement: result = result.replaceAll("([a-zA-Z]+)0([a-zA-Z\s0]+)", "$1o$2");

Answer 3

(\B0\B|\B0|0\B)

Matches three cases:

• 0 in the middle of a word, e.g. "th0se"
• 0 at the end of a word, e.g. "lid0"
• 0 at the start of a word, e.g. "0thers"

So, `result.replaceAll("(\B0\B|\B0|0\B)", "o");

However this will also replace I have 101 dogs with I have 1o1 dogs, so you will probably want to further refine your expression, or logic.

While a single regex can be written to achieve this, I feel that it would be simpler and clearer to achieve it in ordinary Java code:

• split the line into tokens (a token can be a chunk of whitespace or a chunk of non-whitespace - you could capture these using the regex (\s+|\S+) and a Matcher.
• for each token:
  • if it's whitespace, leave it alone
  • if it consists entirely of numbers and symbols, leave alone
  • else word.replace('0','o')
  • output token

Answer 4

If you don't want to use complex regex, You can iterate over string and do the same.

char c[] = new char[s.length()];
for(int i=0;i<s.length();i++){
    if(s.charAt(i) == '0'){
        c[i] = 'o';
    }else{
        c[i] = s.charAt(i);
    }
}
 //now convert to string.
s = String.valueOf(c);

And for only inside the words, you can check following:

    String s = "I like th0se b00ks ... 100 pages";
    char c[] = new char[s.length()];
    for(int i=1;i<s.length()-1;i++){
        if(s.charAt(i) == '0' && !Character.isDigit(s.charAt(i+1)) && !Character.isDigit(s.charAt(i-1))){
            c[i] = 'o';
        }else{
            c[i] = s.charAt(i);
        }
    }

    //check corner conditions.
    if(s.length() >=1 && !Character.isDigit(s.charAt(1)) && s.charAt(0) == '0'){
        c[0] = 'o';
    }

    if(s.length() >= 2 &&!Character.isDigit(s.charAt(s.length()-2)) && s.charAt(s.length()-1) == '0'){
        c[s.length()-1] = 'o';
    }

    //now convert to string.
    s = String.valueOf(c);
    System.out.println(s);

Answer 5

Try: result = result.replaceAll("(\\w+)0(\\w+)", "$1o$2");

Using the input: "I don't like th0se books 00 1230"

You get: "I don't like those books 00 1230"

EDIT:

If you use: result = result.replaceAll("([a-zA-Z]+)0([a-zA-Z]+)", "$1o$2");, it should work for the "I don't like th0se books 00 1230 1230456" string too.

Answer 6

You could make use of sed command and pass it to java as an array sed -i s/0/o/g filename

-i - Changes are saved to new file

s - This is for the search

0 - character to be searched for

o - character to be inserted

To check how to use sed as an array in Java, check this link How to run sed command from java code

Let me know if this works for you