How can Separate a number from a text in Android?

Question

this is my code :

String addchar = "";
String tempchar;
int len = strline.length();
char[] chars = strline.toCharArray();
int amount = 0;

for (int i = 0; i < len; i++) {
    tempchar = String.valueOf(chars[i]);
    if (tempchar == "0" || tempchar == "1" || tempchar == "2" || tempchar == "3" || tempchar == "4" || tempchar == "5" || tempchar == "6" || tempchar == "7" || tempchar == "8" || tempchar == "9") {
        addchar=tempchar+addchar;
    }
}

amount=Integer.parseInt(addchar);

but when run this code , I see that amount is empty! I want to extract , the number that there is in strline

What sort of input are you expecting? – Michael Dodd Aug 03 '17 at 13:51 — Michael Dodd, Aug 03 '17 at 13:51

score 1 · Answer 1 · answered Aug 03 '17 at 13:52

1

try this use Matcher

  Matcher matcher = Pattern.compile("\\d+").matcher("a22dsdddd212");
while(matcher.find()) {
    Log.e("number :-> ",matcher.group()+"");
}

answered Aug 03 '17 at 13:52

AskNilesh

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Michael Dodd · Accepted Answer · 2017-08-03T16:52:23.267

1

Slightly less elegant than Nilesh's answer, but as an alternative:

StringBuilder sb = new StringBuilder();

for (char c : strline.toCharArray()) {
    if ((sb.length() == 0 && "-".equals(c)) || Character.isDigit(c)) sb.append(c);
}

int amount = Integer.parseInt(sb.toString());

Edit Amended to allow for initial negative sign

edited Aug 03 '17 at 16:52

answered Aug 03 '17 at 13:58

Michael Dodd

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I have another problem : My number is signed How can I get number sign (-or+)? – Azade Aug 03 '17 at 16:17
Updated my answer. It'll allow for a minus sign so long as no digits have yet been found. Ignoring + as lack of a minus will infer a positive value. – Michael Dodd Aug 03 '17 at 16:53

score 0 · Answer 3 · edited Aug 03 '17 at 14:01

0

If you want all numeric char, you can use replaceALL in this way:

String numericString = strline.replaceAll("[^0-9]", "");

then use ParseInt.

Hope it helps.

edited Aug 03 '17 at 14:01

Fusselchen

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answered Aug 03 '17 at 13:55

Andrea Ebano

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Also an option, though using \\d may be better – Aug 03 '17 at 14:12
`\d` may not work in comination with parseInt. See https://stackoverflow.com/questions/890686/should-i-use-d-or-0-9-to-match-digits-in-a-perl-regex for some differences between `\d`and `0-9` – Fusselchen Aug 03 '17 at 14:25
@AzadGh If any of these answers have helped, please accept the answer by clicking the ✓ – Michael Dodd Aug 03 '17 at 15:26
@AzadGh Click the check to the left of my answer to accept it – Andrea Ebano Aug 03 '17 at 15:30
I have another problem My number is signed How can I get number sign ? – Azade Aug 03 '17 at 16:04

How can Separate a number from a text in Android?

3 Answers3