Remove leading and trailing whitespace in Dart

In Dart, you can remove leading and trailing whitespaces from a string using the trim() method. Here's an example:

String str = "    Hello, World!   ";
String trimmedStr = str.trim();
print(trimmedStr); // Output: "Hello, World!"

In the above example, the original string " Hello, World! " contains leading and trailing whitespaces. The trim() method removes those whitespaces and returns the new string "Hello, World!".

You can also use trimLeft() and trimRight() methods to remove leading and trailing whitespaces respectively. Here's an example:

String str = "    Hello, World!   ";
String leftTrimmedStr = str.trimLeft();
String rightTrimmedStr = str.trimRight();
print(leftTrimmedStr); // Output: "Hello, World!   "
print(rightTrimmedStr); // Output: "    Hello, World!"

In the above example, the trimLeft() method removes leading whitespaces and returns the new string "Hello, World! ". Similarly, trimRight() method removes trailing whitespaces and returns the new string " Hello, World!".