Converting a String to different characters using String arrays

Question

private void convertToNumeric() {

    for (int i = 0; i < this.CONVERT_TO_NUMERIC.length; i++) {
        for (int j = 0; j < this.INPUT_FROM_USER.length(); j++) {



        }
    }



}



private String INPUT_FROM_USER = "";
private final String[][] CONVERT_VALUES = { {"1", "w"}, { "2", "e"}, {"3", "r"}, 
                                            {"4", "s"}, {"5", "d"}, {"6", "f"}, {"7", "z"},
                                            { "8", "x"}, {"9", "c"} };

private final String[][] CONVERT_TO_NUMERIC = { {"abc", "2"}, {"def", "3"}, {"ghi", "4"},
                                                {"jkl", "5"}, {"mno", "6"}, {"pqrs", "7"},
                                                {"tuv", "8"}, {"wxyz", "9"} };

Can someone please give me some guidance on how I'd go about converting an input to the character specified in the String arrays?

Here's an example.

User inputs "Hello world"
Searches the String array and converts each character in the String to the given number
Outputs "43556 96753"

If the first value of the array contains the character, it will get replaced with the number.

I'm not asking to be spoonfed, I just need a little guidance on how to get started. Thanks in advance.

Is that character to number 1 to 1 mapping , I ask this because I see two arrays `CONVERT_TO_NUMERIC ` and `CONVERT_VALUES ` ! — AllTooSir, May 27 '13 at 11:36
How "Hello World" becomes "43556 96753" . Is 'h'='4', 'e'='3' ? — AllTooSir, May 27 '13 at 11:37
Each character is replaced with the corresponding number in CONVERT_TO_NUMERIC, if the first String contains the letter, it's replace with the number. — user1848712, May 27 '13 at 12:10

score 1 · Answer 1 · answered May 27 '13 at 11:36

1

This seems like a job, far better suited to a HashMap. Here is the documentation.

For example, you can use:

HashMap<String, String> map = new HashMap<String, String>();

map.put("H", "10");
map.put("I", "11");

Then when an input string arrives:

String value = "Hello";
String response = "";

for(char c : value)
{
    response += map.get(String.valueOf(c));
}

answered May 27 '13 at 11:36

christopher

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Is there a way to use the contains method with HashMap or something similar? Because I'm using values.put("abc", "2"); and it's returning null when I'm trying to get the values because it doesn't exist – user1848712 May 27 '13 at 12:11
[This question](http://stackoverflow.com/questions/3430170/how-to-create-a-2-way-map-in-java) seems to point you in the right direction. – christopher May 27 '13 at 13:25

Joop Eggen · Answer 2 · 2013-05-27T12:41:06.193

1

Turn it around, and start with the tables (= what to do):

String value = "Hello world";

for (String[] mapping : CONVERT_TO_NUMERIC) {
    value = value.replaceAll("(?i)[" + mapping[0] + "]", mapping[1]);
    // Case insensitive "[abc]" -> "2" etcera.
}

// value now is "43556 96753"

The same for the other table now.

edited May 27 '13 at 12:41

answered May 27 '13 at 11:41

Joop Eggen

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Yeah thanks, except I'm not trying to replace the whole String, but each individual character. I'm not sure if this will work in the way I want it to – user1848712 May 27 '13 at 12:12

Converting a String to different characters using String arrays

2 Answers2