24 undefined and not-defined.html

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<html lang="en">
    <head><title>undefined and not-defined</title>
    </head>
    <body>
        from video 7 of nameste javascript
        <script>
            /*
            "undefined" indicates that a variable has been declared but not given a value, while
            "not defined" indicates that a variable does not exist.
            */

            console.log(x); // undefined : because we have not assigned any value to x yet
            var x=7; 

            //console.log(a); // o/p: not defined because we have not allocated any memory to a (or a doesn't exist)
            
            console.log(x); // prints value of x

            var b;
            console.log(b);  // undefined
            b=10;
            console.log("b=",b); // 10
            b="value";
            console.log("now b=",b); // value
        </script>
    </body>
</html>