Furthermore you can concatenate different conditions with "or” or “and” statements, to test whether either statement is true, or both are true, respectively.
In JavaScript “or” is written as || and “and” is written as &&.
Say you want to test if the value of x is between 10 and 20—you could do that with a condition stating:
if(x > 10 && x < 20) {
...
}
If you want to make sure that country is either “England” or “Germany” you use:
if(country === 'England' || country === 'Germany') {
...
}
Note: Just like operations on numbers, Condtions can be grouped using parenthesis, ex: if ( (name === "John" || name === "Jennifer") && country === "France").
{% exercise %}
Fill up the 2 conditions so that primaryCategory equals "E/J" only if name equals "John" and country is "England", and so that secondaryCategory equals "E|J" only if name equals "John" or country is "England"
{% initial %}
var name = "John";
var country = "England";
var primaryCategory, secondaryCategory;
if ( /* Fill here / ) { primaryCategory = "E/J"; } if ( / Fill here */ ) { secondaryCategory = "E|J"; } {% solution %} var name = "John"; var country = "England"; var primaryCategory, secondaryCategory;
if (name === "John" && country === "England") { primaryCategory = "E/J"; } if (name === "John" || country === "England") { secondaryCategory = "E|J"; } {% validation %} assert(primaryCategory === "E/J" && secondaryCategory === "E|J"); {% endexercise %}