1function doSomething(x) {
2  if(typeof(x) === 'string') {
3    alert('x is a string')
4  } else if(typeof(x) === 'number') {
5    alert('x is a number')
6  }
7}

1console.log(typeof "how are you?")
2"string"
3console.log(typeof false) / console.log(typeof true)
4"boolean"
5console.log(typeof 100)
6"number"

1> typeof "foo"
2"string"
3> typeof true
4"boolean"
5> typeof 42
6"number"
7
8if(typeof bar === 'number') {
9   //whatever
10}

1typeof("string"); //string
2typeof(123); //number

1typeof(variable)

1typeof("iAmAString");//This should return 'string'
2//NO camelCase, as it is a JS Keyword