Question

How to use new.target to detect whether a function was called using the new operator in JavaScript

Answer 1

function f() {
  if (!new.target) { throw 'f() called without new'; }

  console.log('f() called without new')
}

try {
  f();
} catch (e) {
  console.log(e);
}



/*
run:

f() called without new

*/

 

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Answer 2

function f() {
  if (!new.target) { throw 'f() called without new'; }

  console.log('f() called with new')
}

let o = new f();




/*
run:

f() called with new

*/

 

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