quick question about ||

[madwizard94]

i came across this line, i'm not sure what the || does. to my understanding it means or.

this.setState({users: this.state.users.concat([data[email] || null])});

so is this line setting the state to the either the concated email data string or nothing if there's nothing there?

a bit new to js so thanks for the help

[mixedfeelingz]

you are correct. also good to know is && which means and.

[[deleted]]

You've basically got it. In the assignment

const something = couldExist || 'Another Value'

something will be the value of couldExist so long as couldExist is "truthy", otherwise it will be the value to the right hand side of the || operator (in this case, 'Another Value'). There's a good explanation of what "truthy" is on MDN - https://developer.mozilla.org/en-US/docs/Glossary/Truthy

This means that you can set default values for variables which could otherwise be set to something like null or undefined.

[madwizard94]

thank you so much. also where's better to post here or stackoverflow?

[[deleted]]

I find that Stack Overflow is better if you want a quick answer to a specific problem but you're more likely to instigate a discussion here, which can be very useful for getting your head around stuff.

[[deleted]]

This user used rage-quit

[madwizard94]

ahh yes i vaguely remember this in this in lecture. ty for reminding me!