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re: More JavaScript Mistakes You May be Making VIEW POST

FULL DISCUSSION
 

its also possible to check the value if its null or undefined with this.

value ? 'has value' : 'undefined or null'
 

This wouldn't be 100 percent reliable since 0, empty string, and NaN are also falsy.

So you would get the second choice returned in those cases as well.

 

Yea, i guess you could just use the snippet if you wanted to check if theres really a value or not. I think it could be useful sometimes when you are getting a value from an api and you don't have access into the backend funtions, and they just throw either undefined null 0 or empty string

My view is to have undefined something only the runtime is allowed to set, while null is something I deliberately set.
This way you get a hint who messed up if the value is missing.

As long as we remember the difference, I think it's OK. Also, we have to be consistent in how we use them.

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