How to trim white space from all elements in array

问题:

I was just wondering what the best way to remove the white space from all the elements of a list would be.

For example if I had String [] array = {" String", "Tom Selleck "," Fish "} How could I get all the elements as {"String","Tom Selleck","Fish"}

Thanks!

回答1:

Try this:

String[] trimmedArray = new String[array.length];
for (int i = 0; i < array.length; i++)
    trimmedArray[i] = array[i].trim();

Now trimmedArray contains the same strings as array, but without leading and trailing whitespace. Alternatively, you could write this for modifying the strings in-place in the same array:

for (int i = 0; i < array.length; i++)
    array[i] = array[i].trim();

回答2:

Another java 8 lambda option :

String[] array2 = Arrays.stream(array).map(String::trim).toArray(String[]::new);

And the ugly but optimized version without new array creation

Arrays.stream(array).map(String::trim).toArray(unused -> array);

Original "array" is modified.

回答3:

Add commons-lang3-3.1.jar in your application build path. Use the below code snippet to trim the String array.

String array = {" String", "Tom Selleck "," Fish "};
array = StringUtils.stripAll(array);

回答4:

In Java 8, Arrays.parallelSetAll seems ready made for this purpose:

import java.util.Arrays;

Arrays.parallelSetAll(array, (i) -> array[i].trim());

This will modify the original array in place, replacing each element with the result of the lambda expression.

回答5:

I know this is a really old post, but since Java 1.8 there is a nicer way to trim every String in an array.

Java 8 Lamda Expression solution:

List<String> temp = new ArrayList<>(Arrays.asList(yourArray));
temp.forEach(e -> {temp.set((temp.indexOf(e), e.trim()});
yourArray = temp.toArray(new String[temp.size()]);

with this solution you don't have to create a new Array.
Like in Óscar López's solution

回答6:

You can just iterate over the elements in the array and call array[i].trim() on each element

回答7:

Not knowing how the OP happened to have {" String", "Tom Selleck "," Fish "} in an array in the first place (6 years ago), I thought I'd share what I ended up with.

My array is the result of using split on a string which might have extra spaces around delimiters. My solution was to address this at the point of the split. My code follows. After testing, I put splitWithTrim() in my Utils class of my project. It handles my use case; you might want to consider what sorts of strings and delimiters you might encounter if you decide to use it.

public class Test {
    public static void main(String[] args) {
        test(" abc def  ghi   jkl ", " ");
        test("  abc; def  ;ghi  ; jkl; ", ";");
    }

    public static void test(String str, String splitOn) {
        System.out.println("Splitting \"" + str + "\" on \"" + splitOn + "\"");
        String[] parts = splitWithTrim(str, splitOn);
        for (String part : parts) {
            System.out.println("(" + part + ")");
        }
    }

    public static String[] splitWithTrim(String str, String splitOn) {
        if (splitOn.equals(" ")) {
            return str.trim().split(" +");
        } else {
            return str.trim().split(" *" + splitOn + " *");
        }
    }
}

Output of running the test application is:

Splitting " abc def  ghi   jkl " on " "
(abc)
(def)
(ghi)
(jkl)
Splitting "  abc; def  ;ghi  ; jkl; " on ";"
(abc)
(def)
(ghi)
(jkl)

回答8:

String val = "hi hello prince";
String arr[] = val.split(" ");

for (int i = 0; i < arr.length; i++)
{   
     System.out.print(arr[i]);
}