How to Check if String contains only Alphabets in Dart - Step by Step Examples

How to Check if String contains only Alphabets in Dart ?

Answer

To check if a string contains only alphabets in Dart, you can use regular expressions or iterate through each character and check if it is an alphabet.

✐ Examples

1 Check if String contains only Alphabets using regular expression

In this example,

We create a regular expression pattern that matches alphabets only.
We use the RegExp class and its hasMatch method to check if the string matches the pattern.
If the string contains only alphabets, we set containsOnlyAlphabets to true, otherwise false.
Finally, we print the result to the console.

Dart Program

void main() {
  String str1 = 'HelloWorld';
  RegExp regex = RegExp(r'^[a-zA-Z]+\$');
  bool containsOnlyAlphabets = regex.hasMatch(str1);
  print('String contains only alphabets: \$containsOnlyAlphabets');
}

Output

String contains only alphabets: true

2 Check if String contains only Alphabets using loop to check each character

In this example,

We create a variable named str2 with a value of 'Hello123'.
We iterate through each character in the string and check if it is an alphabet using ASCII values.
If all characters are alphabets, we set containsOnlyAlphabets to true, otherwise false.
Finally, we print the result to the console.

Dart Program

void main() {
  String str2 = 'Hello123';
  bool containsOnlyAlphabets = true;
  for (int i = 0; i < str2.length; i++) {
    if (!(str2.codeUnitAt(i) >= 65 && str2.codeUnitAt(i) <= 90) && !(str2.codeUnitAt(i) >= 97 && str2.codeUnitAt(i) <= 122)) {
      containsOnlyAlphabets = false;
      break;
    }
  }
  print('String contains only alphabets: \$containsOnlyAlphabets');
}

Output

String contains only alphabets: false

Summary

In this tutorial, we learned How to Check if String contains only Alphabets in Dart language with well detailed examples.

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