I am trying to write a simple regex that matches all class names in a file. It should match them either with or without a space before the curly bracket.
E.g.
class myClass {...}
Returns ['myClass']
class myClass {....} class Foo{...}
Returns ['myClass', 'foo'].
And so on.
This is what I have so far but it doesnt seem to be working when there is no space befor ethe bracket:
([a-zA-Z_{1}][a-zA-Z0-9_]+)(?=\{)
Use positive lookbehind and lookahead :
const str = 'class myClass {....} class Foo{...} class Bar { /* this is a class comment */ }';
const result = str.match(/(?<=class\s)(\w+)(?=\s*{)/g);
console.log(result)
If you want to get not only class declarations but also class instances you might use something like (considering class names follow convention & start from a capital letter):
const sample = `class Foo {};
$a = new Bar;
const myConst = 42;
function thisIsAFunction(){
console.log(123);
}
class FlowController{}
let laser = new LaserActivator()
var myVar;class NewClass{...};
`;
const classExp = /[\s;][A-Z]\w+?[({\s;]/gm;
sample.match(classExp); //[" Foo ", " Bar;", " FlowController{", " LaserActivator(", " NewClass{"]
Or if you don't want additional characters like spaces, semicolons, etc. to be present, you could use lookahead (something like this):
/[\s;][A-Z]\w+?(?=([\({\s]))/gm;
