Javascript Regular Expression - 3 Methods and 5 Properties (Reference)

https://webdevfix.com/3-regular-expression-methods-and-5-regular-expression-properties-in-javascript

Tech:

Javascript

Since:

2 years ago

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The javascript regular expression object is used to match text against a pattern. It returns a regular expression object which has 3 methods and 5 properties.

Tests for a match in a string. Returns the first match.

var str = "Fallinfo";
var patt = /[A-Z]/g;
var x = patt.exec(str);
// F

Tests for a match in a string. Returns true or false.

var str = "Fallinfo";
var patt = /[A-Z]/g;
var x = patt.test(str);
// true

Returns the string value of the regular expression.

var str = "Fallinfo";
var patt = /[A-Z]/g;
var res = patt.toString();
// /[A-Z]/g

Checks whether the "g" modifier is set.

var str = "Fallinfo";
var patt = /[A-Z]/g;
var x = patt.global;
// true

Checks whether the "i" modifier is set.

var str = "Fallinfo";
var patt = /[A-Z]/i;
var x = patt.ignoreCase;
// true

Specifies the index at which to start the next match. Only works if the "g" modifier is set.

var str = "Fallinfo Fallinfo Fallinfo";
var patt = /in/g;

while (patt.test(str) == true) {
  console.log(patt.lastIndex);
}

// 6
// 15
// 24

Checks whether the "m" modifier is set.

var str = "Fallinfo";
var patt = /[A-Z]/m;
var x = patt.multiline;
// true

Returns the text of the RegExp pattern.

var str = "Fallinfo";
var patt = /[A-Z]/g;
var x = patt.source;
// [A-Z]