Split a String only on the First Occurrence of a Character

Split a String only on the First Occurrence of a Character #

Use the String.split() method with array destructuring to split a string only on the first occurrence of a character, e.g. const [first, ...rest] = str.split('-');.

The array destructuring syntax will capture the two parts of the string in separate variables.

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const str = 'try-again-later';
const [first, ...rest] = str.split('-');

console.log(first); // 👉️ try
console.log(rest); // 👉️ ['again', 'later']

const remainder = rest.join('-');
console.log(remainder); // 👉️ again-later

We used the String.split method to split the string on a hyphen (-).

We used array destructuring assignment to assign the first element of the array to the first variable.

At this point, the rest variable is an array containing 2 elements - ['again', 'later'].

Lastly, we used the Array.join method to join the contents of the rest array with a hyphen and to get the remainder of the string - again-later.

Alternatively, you can use the slice method.

Split a String only on the First Occurrence of a Character using Array.slice() #

To split a JavaScript string only on the first occurrence of a character, call the slice() method on the string, passing it the index of the character + 1 as a parameter.

The slice method will return the portion of the string after the first occurrence of the character.

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const str = 'try-again-later';

const after = str.slice(str.indexOf('-') + 1);
console.log(after); // 👉️ again-later

const before = str.slice(0, str.indexOf('-'));
console.log(before); // 👉️ try

The first example shows how to get the part after the last occurrence of a character.

The parameter we passed to the String.slice method is the start index - the index of the first character to be included in the new string.

The second example shows how to get the part before the first occurrence of the character.

In this scenario, we start at index 0 and go up to, but not including the index of the first occurrence of the supplied character.