What happen if I declare a variable without a keyword? [Js]

Question

Suppose I write like this: name = "Tom"
Is the variable 'name' is var by default?
This can print in console without an error. So what's happening in behind the scene?

Answer 1

Variables can be declared and initialize without the var keyword. However, a value must be assigned to a variable declared without the var keyword. The variables declared without the var keyword are global variables.

Answer 2

There's a risk for accidental reassignment of variables defined without `var`, `let` or `const` specifier.

// global space
myName = "real slim shady";

function blah()
{
myName = "fake slim shady";
}

A call to blah() will reassign variable <myName> accidentally.

You should be careful of that ...

Answer 3

Chris Coder is this a potential walrus??!