Best way to convert an array of integers to a string in Java

java arrays string integer

17,763

Solution 1

Simplest performant approach is probably StringBuilder:

StringBuilder builder = new StringBuilder();
for (int i : array) {
  builder.append(i);
}
String text = builder.toString();

If you find yourself doing this in multiple places, you might want to look at Guava's Joiner class - although I don't believe you'll be able to use it for primitive arrays. EDIT: As pointed out below, you can use Ints.join for this.

Solution 2

   int[] x = new int[] {3,4,5};
   String s = java.util.Arrays.toString(x).replaceAll("[\\,\\[\\]\\ ]", "")

Update

For completeness the Java 8 Streams solution, but it isn't pretty (libraries like vavr would be shorter and faster):

String s = IntStream.of(x)
  .mapToObj(Integer::toString)
  .collect(Collectors.joining(""));

Solution 3

Try with this - you have to import java.util.Arrays and then -

String temp = Arrays.toString( intArray ).replace(", ", "");
String finalStr = temp.substring(1, temp.length()-2);

Where intArray is your integer array.

Solution 4

StringBuffer str =new StringBuffer();
for(int i:x){  
str.append(i);
}

You need to read all once at least.

Solution 5

public static void main(String[] args) {
    int[] dice = {1, 2, 3, 4, 5, 0};
    String string = "";

    for (int i = 0; i < dice.length; i++) {
        string = string + dice[i];
    }

    System.out.print(string);   

}

This is another way you can do it. Basically just makes a for-loop that accesses every element in the integer array and adds it to the string.

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Author by

didxga

I am playing code for fun!

Updated on June 05, 2022

Comments

didxga almost 2 years

In Java, I have an array of integers. Is there a quick way to convert them to a string?

I.E. int[] x = new int[] {3,4,5} x toString() should yield "345"
Landei over 13 years

That yields "[3,4,5]", not "345"
Sachin Shanbhag over 13 years

@Landei - yeah saw that.. Try now. Have edited the answer now
Jon Skeet over 13 years

That's going to give "3 4 5" now instead of "345".
Sachin Shanbhag over 13 years

@Jon Skeet - Yep. Sorry, replace method is adding a space. Edited again. Thanks.
Sachin Shanbhag over 13 years

@didxga - yes, its surely tricky and within two lines of code. Admit I got it from this link if you need more info - daniweb.com/forums/thread14183.html
Jon Skeet over 13 years

Personally I'd rather use my five lines of simple code than two lines of code which have already proved themselves relatively hard to get right :)
didxga over 13 years

Wow, I am lucky, I found that your answer to my question is just your 10000th answer in Stackoverflow,am i right? Congrats!
Ashish Patil over 13 years

I have up-voted your answer. But just a curious? What is more costly (time consuming)? StringBuilder.append(int) or y = y*10 + x; ? I know the primitives will work only till the Integer.MAX_VALUE, but if we always have less than that result, then what would be better?
Etienne Neveu about 13 years

Guava's Joiner won't work for int primitives (it works with Objects), but Ints.join("", intArray) will: guava-libraries.googlecode.com/svn/tags/release09/javadoc/co‌m/…
Code almost 11 years

I have made use of list here
Mat over 9 years

Please don't (badly) copy-paste other answers into your own. (stackoverflow.com/a/16811343/635608)