WDI Fundamentals

WDI Fundamentals Unit 8


Your Turn Your Turn

You should see the following code in the editor window:

var x;
/* Your Expression */

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JS Bin on jsbin.com

1) Write an expression that assigns x to the variable value, so long as x is not undefined or null; if x is undefined or null, the expression should set value to 100. x is equal to undefined when no value has been assigned (e.g., var x;), but you could also assign it the value of null (var x = null;), and both of these values would be "falsey." After you click the run button, you can test this in the console tab by typing value, and then enter or return. Test your expression for several different values of x, including null. does it behave like you expect?

2) Next, replace that expression with one that assigns null to value if x is null or undefined, but otherwise assigns 50 (regardless of x's actual value).

3) Finally, write an expression that assigns true to value if x is an empty string ('') but otherwise assigns false.

Were you able to get all of your expressions to work? If so, nice job!

Stuck? Check out the solutions to see what you can do.


Ready for another quiz? Here we go!