# Top 10 String methods you should know

In today’s string of articles on Top 10 methods, we will look at some useful utility methods that come with the `String` type.

You can use these methods combined with inbuilt support for template literals, allowing for effective manipulation of strings:

```dart
var str1 = 'Lorem';
var str2 = '$str1 ipsum'; // String interpolation
var str3 = '''Multi
Line
$str1 $str2'''; // Multi-line strings
```

## **1\. contains()**

This allows you to check whether the specified string exists:

```dart
str1.contains('rem'); // true
```

## **2\. startsWith()**

This allows you to check whether the string starts with the specified characters:

```dart
str2.startsWith('Lorem'); // true
str3.startsWith('Noorem'); // false
```

## **3\. endsWith()**

Checks whether the string ends with the specified characters:

```dart
str3.endsWith('ipsum'); // true
str3.endsWith('oopsum'); // false
```

## **4\. toLowerCase(), toUpperCase()**

Converts the string to lowercase and uppercase formats:

```dart
str1.toLowerCase(); // lorem
str1.toUpperCase(); // LOREM
```

## **5\. split()**

Splits the string at the matching pattern, returning a list of substrings:

```dart
str3.split('\n'); // ['Multi', 'Line', 'Lorem Lorem ipsum'];
```

## **6\. splitMapJoin()**

Splits the string, converts each list item, and combines them into a new string:

```dart
str3.splitMapJoin(RegExp(r'^', multiLine: true), // Matches the beginning of each line
  onMatch: (m) => '**${m.group(0)} ', // Adds asterisk to the line beginning
  onNonMatch: (n) => n); // Leaves non matches as is
/*
Output: 

** Multi
** Line
** Lorem Lorem ipsum

*/
```

## **7\. indexOf(), lastIndexOf()**

Returns the position of the first and last matches of the given pattern:

```dart
str3.indexOf('rem'); // 13
str3.lastIndexOf('rem'); // 19
```

Both methods also take in an optional parameter specifying the index to begin the search from:

```dart
str3.lastIndexOf('rem', 18); // 13
```

## **8\. trim()**

Removes leading and trailing whitespaces:

```dart
"   $str2  ".trim(); // 'Lorem ipsum'
```

## **9\. padLeft(), padRight()**

Pads the string on the left and right with the given padding if the string is less that the specified length:

```dart
str1.padLeft(8, 'x'); // xxLorem
str1.padRight(8, 'x'); // Loremxx
```

## **10\. replaceAll()**

Replaces all substrings that match the specified pattern with the replacement string:

```dart
str2.replaceAll('e', 'é'); // Lorém
```

## Conclusion

I hope this was insightful and if this is your first exposure to Dart, read my [first steps tutorial](https://dev.to/graphicbeacon/learn-dart-before-you-flutter-2997) to grasp the basics. The code snippets for this article are available on [DartPad](https://dartpad.dartlang.org/abea509cc44de22b5c714c686b17c2ce).

**Like, share and** [**follow me**](https://twitter.com/creativ_bracket) ? for more articles on Dart. Thanks so much.

## **Quicklinks**

1. [String class Documentation](https://api.dartlang.org/stable/2.1.1/dart-core/String-class.html)
    
2. [**Free Dart screencasts on Egghead.io**](https://egghead.io/instructors/jermaine-oppong)