Logical Operators

In JavaScript conditions can be combined using and/or logic.

OR

• is denoted with '||'
• At least one conditions must evaluate to true in order for the statement to be considered true.
• If all conditions evaluate to false the statement is false.

if(name === 'john' || name === 'jane') {  console.log('name was either john or jane');} 

AND

• is denoted with '&&'
• All conditions must evaluate to true in order for the statement to be true.
• If a single condition evaluates to false the entire statement is false.

if(name === 'John' && age === 25) {  console.log('Both conditions are true')} else {  consol.log('One or more of the conditions evaluated to false')}

NOT

• If you want to negate a condition you prefix it with '!'

if(user.role !== 'admin') {  console.log('user does not have the admin role')}