Hyphen search in a string using java

Question

I am trying to find the occurrence of hyphen - in a string "TC 1 - TC 24". For that I used

"TC 1 - TC 24".contains(" \\-")

But the above expression doesn't returns true. What am I doing wrong?

The code looks like:

if("TC 1 - TC 24".contains(" \\- ") == true) {

   //print something
}

*Hint:* The parameter to [`contains()`](https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#contains-java.lang.CharSequence-) is not a regex, it's a literal value. Use `contains(" - ")`. --- Also, even if the parameter had been a regex, you still wouldn't need the ``\\``, since a `-` is not a special character in a regex outside a `[]` character class. — Andreas, Aug 29 '18 at 17:32
Possible duplicate of [Occurrences of substring in a string](https://stackoverflow.com/questions/767759/occurrences-of-substring-in-a-string) — , Aug 29 '18 at 17:33
*Hint:* Using `== true` is unnecessary. See [Is it bad to explicitly compare against boolean constants e.g. if (b == false) in Java?](https://stackoverflow.com/q/2661110/5221149) — Andreas, Aug 29 '18 at 17:39
@weizenkeimhugo I don't see how that is a duplicate of this question. — Mark Rotteveel, Aug 31 '18 at 16:53

score 1 · Answer 1 · edited Mar 16 '19 at 05:42

Contains keyword in java returns true if provided string contains the specified sequence of char values

So, the below string returns True as it contains hyphen. But, we cannot count the no. of times hyphen occurs.

if ("TC 1 - TC- 24".contains("-")) {
    System.out.println("It containes hyphen ");
}

I am finding occurrence of hyphen using the below code:

public static int findCharInString(String input,char inputChar) {
    int counter=0;
    for (int i = 0; i < input.length(); i++) {
        if(input.charAt(i)==inputChar) {
            counter++;
        }
    }
    return counter;
}

score 0 · Answer 2 · answered Aug 29 '18 at 18:08

0

You could use something like:

if ( yourString.matches("[\\p{Alnum} ]+ - [\\p{Alnum} ]+") )
{
    System.out.println("String contains a hyphen")
}

the \\p is a POSIX character class for Alphanumeric

answered Aug 29 '18 at 18:08

spectrum

319
3
11

score 0 · Answer 3 · edited Mar 16 '19 at 05:41

You can use the indexOf method of String class, as indexOf searches the String from given String. If it finds then it will return the index of that String otherwise it will return -1. So you can easily use indexOf. I have given below code please go through with it.

public static void main(String[] args) {
    String hypen="12-35";
    int index = hypen.indexOf("-");
    if (index != -1) {
        System.out.println("True");
    } else {
        System.out.println("False");
    }
}

score -1 · Answer 4 · edited Aug 29 '18 at 20:43

-1

String str = "TC 1 - TC 24";

int str_length = str.length();
for (int i=0; i<str_length; i++) {
    char ch = str.charAt(i);
    if (ch == '-') {
        System.out.println("True");
        break;
    }
}

edited Aug 29 '18 at 20:43

Ilario Pierbattista

3,051
2
30
39

answered Aug 29 '18 at 17:54

wahidd

65
1
5

How does this answer the question? – Nicholas K Aug 29 '18 at 18:06
It will search for '-' throughout the string. If its find one break and return 'true'. – wahidd Nov 11 '18 at 05:50

Hyphen search in a string using java

4 Answers4