The trim()
method removes any leading (starting) and trailing (ending) whitespaces from the specified string.
Example
class Main {
public static void main(String[] args) {
String str1 = " Learn Java Programming ";
System.out.println(str1.trim());
}
}
// Output: Learn Java Programming
Syntax of trim()
The syntax of the string trim()
method is:
string.trim()
Here, string is an object of the String
class.
trim() Parameters
- the
trim()
method doesn't take any parameters
trim() Return Value
- returns a string with leading and trailing whitespace removed
- returns the original string if there is no whitespace in the start or the end of the string
Note: In programming, whitespace is any character or series of characters that represent horizontal or vertical space. For example: space, newline \n
, tab \t
, vertical tab \v
etc.
Example: Java String trim()
class Main {
public static void main(String[] args) {
String str1 = " Learn Java Programming ";
String str2 = "Learn\nJava Programming\n\n ";
System.out.println(str1.trim());
System.out.println(str2.trim());
}
}
Output
Learn Java Programming Learn Java Programming
Here, str1.trim()
returns
"Learn Java Programming"
Similarly, str2.trim()
returns
"Learn\nJava Programming"
As you can see from the above example, the trim()
method only removes the leading and trailing whitespace. It doesn't remove whitespace that appears in the middle.
Remove All Whitespace Characters
If you need to remove all whitespace characters from a string, you can use the String replaceAll() method with proper regex.
class Main {
public static void main(String[] args) {
String str1 = "Learn\nJava \n\n ";
String result;
// replace all whitespace characters with empty string
result = str1.replaceAll("\\s", "");
System.out.println(result); // LearnJava
}
}