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In this article, the editor introduces in detail "how to use substring () in JavaScript". The content is detailed, the steps are clear, and the details are handled properly. I hope this article "how to use substring () in JavaScript" can help you solve your doubts.

The jssubstring () method is used to extract characters that are mediated between two specified subscripts.

Jssubstring () syntax

StringObject.substring (start,stop)

Parameter description

Start is required. A non-negative integer that specifies the position of the first character of the substring to be extracted in the stringObject.

Stop

Optional. A non-negative integer that is 1 more positioned in stringObject than the last character of the substring to be extracted.

If this parameter is omitted, the substring returned will go all the way to the end of the string.

Return value

A new string whose value contains a substring of stringObject whose contents are all characters from start to stop-1, whose length is stop minus start.

Description

The substring returned by the substring () method includes the character at start, but not the character at stop.

If the parameter start is equal to stop, the method returns an empty string (that is, a string of length 0). If start is larger than stop, the method swaps these two parameters before extracting the substring.

Tips and comments

Important: unlike the slice () and substr () methods, substring () does not accept negative parameters.

Jssubstring () instance

Example 1

In this example, we will use substring () to extract some characters from the string:

Varstr= "Helloworld!"

[xss_clean] (str.substring (3))

Output:

Loworld!

Try it yourself.

Example 2

In this example, we will use substring () to extract some characters from the string:

Varstr= "Helloworld!"

[xss_clean] (str.substring (3. 7))

Output:

Low

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