How To Get The Substring Before A Specific Character In JavaScript

Getting the substring before a specific character in JavaScript is a task you often encounter during programming. This article will show you how to get the substring before a specific character in JavaScript. It’s helpful for you. Read on it now.

Get the substring before a specific character in JavaScript

Getting the substring before a specific character in JavaScript is a task you often encounter during programming. Example: You have the string “1000 people visit LearnShareIT per hour”, and you want to get a substring as the number of visitors. The substring you need is the substring before the first ” ” character.

If you want to get the substring before a specific character in JavaScript, you can use the following three methods:

• substr()
• substring()
• split()

Each of the above methods has its uses and properties. We will show you how to use each method to get the substring before a specific character.

Solution 1: Use the substr() method

The substr() method extracts substrings from a string without changing the original string.

Syntax:

string.substr(start, length)

Parameter:

• Start: specified starting position, the index starts from 0.
• Length: a specified number of characters.

Example:

We have the string “1000 people visit LearnShareIT per hour”. We want to get the substring before the first ” ” character.

const visit = '1000 people visit LearnShareIT per hour';
const visitors = visit.substr(0, visit.indexOf(' '));
console.log(visitors);

Output:

1000

The above example uses the substr() method with the first parameter, 0. In the second parameter, we use the indexOf() method. The indexOf() method will return the first position of a specified character, and in this example, the character ” “.

Solution 2: Use the substring() method

Like the substr() method, the substring() method extracts substrings from a string without changing the original string.

Syntax:

string.substring(start, end)

Parameter:

• Start: specified starting position, the index starts from 0.
• End: End position (not including).

Example:

We have the string “1000 people visit LearnShareIT per hour”. We want to get the substring before the first ” ” character.

const visit = '1000 people visit LearnShareIT per hour';
const visitors = visit.substring(0, visit.indexOf(' '));
console.log(visitors);

Output:

1000

Because the second parameter of the substring() method is the end position (but not included), the above code will return the substring of the original string from position 0 to before the first ” ” character position.

Alternatively, you can use the lastIndexOf() method to get the substring before the last occurrence of a specific character.

Solution 3: Use the split() method

The split() method splits the original string into substrings and puts them in an array without mutating the original string.

Syntax:

string.split(separator, limit)

Parameter:

• Separator: a string used for splitting.
• Limit: limit the number of splits.

We will show an example of how to use the split() method similar to the previous two solutions.

Example:

const visit = '1000 people visit LearnShareIT per hour';
const visitors = visit.split(' ');
console.log(visitors[0]);

Output:

1000

The above example uses the split method to get the substring before a specific character. The method’s first parameter is ” “, which means that the original string will be split word by word and put into an array. The word with index 0 is the substring before the first ” ” character.