Why is my JavaScript code behaving strange? -


could explain why delete works in second function not in first?

var myfunction = (function (val) {     delete val;     return val; })(10); console.log(myfunction);   var myfunction1 = (function () {     myvar = "test"     delete myvar;     return myvar; })(); console.log(myfunction1);

the delete operator deleting properties, not objects.

in first function, val variable , can never deleted. in function2 myvar declared using shorthand create property on global object, , properties can deleted. in fact main purpose of delete operator.

also delete operator returns boolean value. can use better understanding of how works eg: in case console.log(delete val); print false , console.log(delete myvar); print true. worth keeping in mind return value based on whether object exists afterwards, not whether delete successful.


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