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JavaScript function declaration v/s arrow function in a browser console

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Apart from the usual conciseness and this arguments, JavaScript's function declaration and arrow functions differ in another practical way.

I often like to develop and test small JavaScript code directly in a browser console.

In this environment, a function declaration has an advantage over an arrow function – I can re-define & re-run a function declaration repeatedly in a browser's console. 

>> function strIdentity(v) {
  return v.toUpperCase();
}
undefined

>> function strIdentity(v) {
  return v.toLowerCase();
}
undefined

>> strIdentity("HELLO");
"hello"

On the other hand, re-running an arrow function, which have to be assigned to a variable to be usable at the top level, would throw a re-declaration error, because the same variable cannot be re-declared again. 

>> const strIdentity = v => v.toLowerCase();
undefined

>> // editing the above script

>> const strIdentity = v => v.toUpperCase();
Uncaught SyntaxError: redeclaration of const strIdentity

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