Concatenate chars to form String in java

Question

Is there a way to concatenate char to form a String in Java?

Example:

String str;
Char a, b, c;
a = \'i\';
b = \'c\';
c = \         


        

Answer 1

Use StringBuilder:

String str;
Char a, b, c;
a = 'i';
b = 'c';
c = 'e';

StringBuilder sb = new StringBuilder();
sb.append(a);
sb.append(b);
sb.append(c);
str = sb.toString();

One-liner:

new StringBuilder().append(a).append(b).append(c).toString();

Doing ""+a+b+c gives:

new StringBuilder().append("").append(a).append(b).append(c).toString();

I asked some time ago related question.

Answer 2

You can use StringBuilder:

    StringBuilder sb = new StringBuilder();
    sb.append('a');
    sb.append('b');
    sb.append('c');
    String str = sb.toString()

Or if you already have the characters, you can pass a character array to the String constructor:

String str = new String(new char[]{'a', 'b', 'c'});

Answer 3

If the size of the string is fixed, you might find easier to use an array of chars. If you have to do this a lot, it will be a tiny bit faster too.

char[] chars = new char[3];
chars[0] = 'i';
chars[1] = 'c';
chars[2] = 'e';
return new String(chars);

Also, I noticed in your original question, you use the Char class. If your chars are not nullable, it is better to use the lowercase char type.

Answer 4

Use str = ""+a+b+c;

Here the first + is String concat, so the result will be a String. Note where the "" lies is important.

Or (maybe) better, use a StringBuilder.

Answer 5

Try this:

 str = String.valueOf(a)+String.valueOf(b)+String.valueOf(c);

Output:

ice

Answer 6

Use the Character.toString(char) method.