The functions of substr() and match() in js

Study the project code and come across a few String and Array methods that have not been used much recently. Review them:
1. substr()
Usage: used in strings Extract the specified number of characters starting from the start subscript;
Return value: a new string containing length characters starting from the start of string (including start);
Syntax: String.substr(start ,length);
Parameter start: required; the starting index of the string to be extracted. Must be a numeric value. If it is a negative number, then this parameter represents the position starting from the end of the string. For example, -1 refers to the last character in the string, -2 refers to the second to last character in the string, and so on.
Parameter length: optional; the number of characters in the substring to be extracted must be a numerical value. If omitted, the substring starting from the String start position to the end will be returned.
Note: The parameters of substr() specify the starting position and length of the substring, so it can be used instead of substring() and slice().
Important: ECMAscript does not standardize this method and therefore discourages its use.

2. match():
Function: Retrieve a specified value in a string, or find a match for one or more regular expressions; similar to indexOf() and lastIndexOf(), but match( ) returns the specified value, not the position of the string;
Syntax:
match(searchvale);
match(regExp);

The above is the detailed content of The functions of substr() and match() in js. For more information, please follow other related articles on the PHP Chinese website!