Given an array of numbers (integers) how would I go about converting it to a string.
I am from JS so in we normally do :
[1 , 2 , 3 , 4 , 5].join(separator)
But Java doesn't seem to do that.
I tried :
array.join(" ")
But that throws an error on that it cannot find symbol.
Here is the code :
class Conv {
public static String findOut(int[] arr) {
return arr.join(" ");
}
}
Java does not provide a join method for arrays. Utility methods can be found in the Arrays class. For example Arrays.toString(values) (documentation) which returns a String in the following format:
[1, 5, 15, 2]
So
String result = Arrays.toString(values);
However, you explicitly want the following format:
1 5 15 2
Therefore, use the StringJoiner class (documentation):
StringJoiner sj = new StringJoiner(" ");
for (int value : values) {
sj.add(value);
}
String result = sj.toString();
Or use the Stream API (documentation) to achieve the same result but in a more functional-style:
String result = Arrays.stream(values) // IntStream
.mapToObj(Integer::toString) // Stream<String>
.collect(Collectors.joining(" "); // String
Arrays.toString(arr) .replaceAll("\\[|]", "") .replace(",", " "); or String.join(" ", IntStream.of(arr) .mapToObj(Integer::toString).collect(Collectors.toList()));. Though the best approach i believe is the joining collector you're using ;-)There's no join method on arrays, instead you can use the stream API's joining collector:
Arrays.stream(arr)
.mapToObj(Integer::toString)
.collect(Collectors.joining(" "));
Java.util.arrays ?import java.util.*; and import java.util.stream.*;error: incompatible types: Object cannot be converted to Stringarr an int[] as shown in your post? String out = "";
for(int i = arr.length){
out = out+arr[i];
}
I think that is what you want
You can use Arrays.toString(int[] a) method.
int[] a = { 1, 2, 3, 4, 5 };
String b = Arrays.toString(a);
System.out.println(b);
It will print [1, 2, 3, 4, 5]
Later you can modify the string for what you want.
Don't forget to import java.util.Arrays.
Bit late to the party here, but in case you're stuck on a pre 1.8 version of java (stream, StringJoiner etc only exist since 1.8), you can just loop through your array and append to a String. I put in a ternary operator to not add the space at the end as I assume you don't want that:
String result = "";
for (int i = 0; i < arr.length; i++) {
result += (i == arr.length - 1) ? arr[i] : arr[i] + " ";
}
java.util.Arrays.toString(...)