JS Regular notes

instanceof REGEXP

REGEXP is a class in JS, similar to an array. However, this creation method does not specify the expression content

var re=new RegExp ();

The simplest regular expression that will match the letter A
Re=new RegExp ("a");
//Overloaded constructor whose second parameter specifies that the case is not case-sensitive
Re=new RegExp ("A", "I");

Among them, for the second parameter, optional parameters, including three kinds:

• G: Full text Search;
• I: Case insensitive;
• M: Multi-line search;

The more common rules for creating regular expressions are: the way literals are declared.

var re=/a/i; //Its effects are the same: Re=new RegExp ("A", "I"), and more commonly used.

Regular expression methods:

• Test method: Returns the Boolean type. It indicates whether the pattern is included in the string being searched. Returns true if present, otherwise false;
• Exec method: Uses the regular expression pattern to look in the string and returns an array that conforms to the regular expression pattern;

Regular Expression properties:

• Source property: Returns the text content of the regular expression. Read-only;

A String that matches the regular expression method:

• Match method: Finds the matching of one or more regular expressions, similar to the Exec method, returns an array

JS Regular notes