How Javascript Assigns `name` Attribute Of Function?

In JavaScript, when I define function like this function aaa(){} I can later access the name by name attribute: aaa.name which will return 'aaa' However, when I define function via

Solution 1:

Javascript declares the name variable of the function by taking the left-hand side argument that is equal to the function, which is 'aaa' in all basic cases. In the first complex definition, you declared state above Javascript will take the variable ab and assign it to a function making the name 'ab'. In the final example, you provided it sets the function equal to a pointer in memory, which is not a defined variable, this sets the name property to an empty string because arr[0] is not a variable name but a pointer to memory. Here is a JSFiddle displaying this.

Solution 2:

Something like this:

Inferred function names

Variables and methods can infer the name of an anonymous function from its syntactic position (new in ECMAScript 2015).

var f = function() {}; 
var object = {   
    someMethod: function() {} 
};
console.log(f.name); // "f" console.log(object.someMethod.name); // "someMethod"

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