I have a Character array (not char array) and I want to convert it into a string by combining all the Characters in the array.
I have tried the following for a given Character[] a:
String s = new String(a) //given that a is a Character array
But this does not work since a is not a char array. I would appreciate any help.
Character[] a = ...
new String(ArrayUtils.toPrimitive(a));
ArrayUtils is part of Apache Commons Lang.
The most efficient way to do it is most likely this:
Character[] chars = ...
StringBuilder sb = new StringBuilder(chars.length);
for (Character c : chars)
sb.append(c.charValue());
String str = sb.toString();
Notes:
charValue() avoids calling Character.toString() ... However, I'd probably go with @Torious's elegant answer unless performance was a significant issue.
Incidentally, the JLS says that the compiler is permitted to optimize String concatenation expressions using equivalent StringBuilder code ... but it does not sanction that optimization across multiple statements. Therefore something like this:
String s = ""
for (Character c : chars) {
s += c;
}
is likely to do lots of separate concatenations, creating (and discarding) lots of intermediate strings.
Iterate and concatenate approach:
Character[] chars = {new Character('a'),new Character('b'),new Character('c')};
StringBuilder builder = new StringBuilder();
for (Character c : chars)
builder.append(c);
System.out.println(builder.toString());
Output:
abc
First convert the Character[] to char[], and use String.valueOf(char[]) to get the String as below:
char[] a1 = new char[a.length];
for(int i=0; i<a.length; i++) {
a1[i] = a[i].charValue();
}
String text = String.valueOf(a1);
System.out.println(text);
It's probably slow, but for kicks here is an ugly one-liner that is different than the other approaches -
Arrays.toString(characterArray).replaceAll(", ", "").substring(1, characterArray.length + 1);
Probably an overkill, but on Java 8 you could do this:
Character[] chars = {new Character('a'),new Character('b'),new Character('c')};
String value = Arrays.stream(chars)
.map(Object::toString)
.collect( Collectors.joining() );
Arrays.asList(chars).stream() can be simplified to Arrays.stream(chars)
char[] chars2 = new char[chars.length]; IntStream.range(0, chars.length).forEach(i -> chars2[i] = chars[i]); String str = new String(chars);
At each index, call the toString method, and concatenate the result to your String s.
how about creating your own method that iterates through the list of Character array then appending each value to your new string.
Something like this.
public String convertToString(Character[] s) {
String value;
if (s == null) {
return null;
}
Int length = s.length();
for (int i = 0; i < length; i++) {
value += s[i];
}
return value;
}
s for null after calling length() on it.
null check is misguided. By default, a null argument is due to a programmer's error, and the best way to deal with it is to throw an NPE.Actually, if you have Guava, you can use Chars.toArray() to produce char[] then simply send that result to String.valueOf().
int length = cArray.length;
String val="";
for (int i = 0; i < length; i++)
val += cArray[i];
System.out.println("String:\t"+val);
