--description--
You can use typeof
to check the data structure, or type, of a variable. This is useful in debugging when working with multiple data types. If you think you're adding two numbers, but one is actually a string, the results can be unexpected. Type errors can lurk in calculations or function calls. Be careful especially when you're accessing and working with external data in the form of a JavaScript Object Notation (JSON) object.
Here are some examples using typeof
:
console.log(typeof "");
console.log(typeof 0);
console.log(typeof []);
console.log(typeof {});
In order, the console will display the strings string
, number
, object
, and object
.
JavaScript recognizes seven primitive (immutable) data types: Boolean
, Null
, Undefined
, Number
, String
, Symbol
(new with ES6), and BigInt
(new with ES2020), and one type for mutable items: Object
. Note that in JavaScript, arrays are technically a type of object.
--instructions--
Add two console.log()
statements to check the typeof
each of the two variables seven
and three
in the code.
--hints--
Your code should use typeof
in two console.log()
statements to check the type of the variables.
assert(__helpers.removeJSComments(code).match(/console\.log\s*\(typeof[\( ].*\)?\)/g).length == 2);
Your code should use typeof
to check the type of the variable seven
.
assert(__helpers.removeJSComments(code).match(/typeof[\( ]seven\)?/g));
Your code should use typeof
to check the type of the variable three
.
assert(__helpers.removeJSComments(code).match(/typeof[\( ]three\)?/g));
--seed--
--seed-contents--
let seven = 7;
let three = "3";
console.log(seven + three);
// Only change code below this line
--solutions--
let seven = 7;let three = "3";console.log(typeof seven);
console.log(typeof three);