//The test method call returns true and false to indicate whether a matching character is found in the specified string — true
//Returns the first string in the string that matches the expression — A
//Returns an array, each of which matches the array of expressions — [a, a, a] note that the global variable g must be used for regularization
//Return the first occurrence position of the matching regular, starting from 0, and return – 1 if not found — 0 * is a bit like indexof*
//It’s easy to replace * this one. Needless to say*
//Split is generally used to divide a string into an array and return an array object, where the value of the 0 subscript of the array is returned
Regularization can simplify many operations. Especially in the form of data validation.