Check if Two Strings are Equal

To check if given two strings are equal in Dart programming, we can use String.compareTo() method or Equal-to comparison operator.

Method 1 – Using String.compareTo()

Call compareTo() method on the first string object, and pass the second string as argument to it. compareTo() returns 0 if the two strings are equal.

Syntax

The syntax of the expression to check if string str1 is equal to the string str2 using compareTo() method is

str1.compareTo(str2) == 0

The above expression returns true if str1 is equal to str2, or false if not.

Example

In the following Dart program, we take two strings: str1, and str2; and check if these two strings are equal using String.compareTo() method.

main.dart

void main() {
    var str1 = 'apple';
    var str2 = 'apple';

    if ( str1.compareTo(str2) == 0 ) {
        print('The two strings are equal.');
    } else {
        print('The two strings are not equal.');
    }
}

Output

The two strings are equal.

Method 2 – Using Equal-to Operator

Equal-to operator can take the two strings as operands, and returns true if the strings are equal, or false if not.

Syntax

The syntax of the expression to check if string str1 is equal to the string str2 using equal-to operator is

str1 == str2

The above expression returns true if str1 is equal to str2, or false if not.

Example

In the following Dart program, we take two strings: str1, and str2; and check if these two strings are equal using equal-to operator.

main.dart

void main() {
    var str1 = 'apple';
    var str2 = 'apple';

    if ( str1 == str2 ) {
        print('The two strings are equal.');
    } else {
        print('The two strings are not equal.');
    }
}

Output

The two strings are equal.

Conclusion

In this Dart Tutorial, we learned how to check if two strings are equal, with examples.