How to Split String By New Line in Typescript?

When working with strings in TypeScript, I was required to split string by a new line in Typescript. In this TypeScript tutorial, I will explain how to do this.

Different operating systems represent new lines with different characters. Windows uses a carriage return followed by a line feed (\r\n), while Unix-based systems, including Linux and macOS, use just a line feed (\n).

Example 1: Split a Simple Multiline String in Typescript

Let’s start with a simple example; below is a simple multiline string in Typescript separated by new lines:

const names = `Robert Doe
Jane Smith
Michael Johnson
Emily Davis`;

To split this string into an array of names, we can use the split() method with a regular expression that matches both \r\n and \n.

const nameArray = names.split(/\r?\n/);
console.log(nameArray);

In this example, the regular expression /\r?\n/ matches a carriage return (\r) followed by a line feed (\n), or just a line feed (\n) on its own.

Here is the complete code:

const names = `Robert Doe
Jane Smith
Michael Johnson
Emily Davis`;
const nameArray = names.split(/\r?\n/);
console.log(nameArray);

You can see the output after I executed the code using VS code.

Example 2: Splitting a String with Mixed New Line Characters

Now, let’s consider a more complex example where the input string could contain a mix of Windows and Unix-style new lines:

const mixedNames = `Christopher Walker\r\nLaura Brown\nKevin Miller\r\nRachel Green`;

We can use the same approach as in the first example to split this string:

const mixedNameArray = mixedNames.split(/\r?\n/);
console.log(mixedNameArray);

Even though the mixedNames string contains both types of new line characters, the regular expression /\r?\n/ ensures that the string is split correctly.

After I executed the code, you can see the output in the screenshot below:

Example 3: Handling Empty Lines

There will be scenarios where you will have empty lines in a string in Typescript. Here is a how to handle empty lines in Typescript.

const namesWithEmptyLines = `Alice Johnson

Bob Lee
Carol King

Derek Hale`;

To split this string and remove any empty lines from the resulting array, you can chain the split() method with filter():

const namesWithoutEmptyLines = namesWithEmptyLines.split(/\r?\n/).filter(name => name.trim() !== '');
console.log(namesWithoutEmptyLines);

Here, the filter() method is used to remove any strings that are empty after being trimmed of whitespace.

Conclusion

Splitting a string by new line characters in TypeScript can be achieved using the split() method with a regular expression. I hope, now you got an idea of how to split a string by new line characters in Typescript using various methods.

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