Look at the console (F12).
Type of, it's an general fuction, to comprobate the type of a data, or variable
It's a received memoty to save data, it's defined with let or var, ECMAC recomend let, so here i'll use let
<script>
let myVar1 = "Hello";
let myVar2 = 123;
console.log("typeof myVar1: "+typeof(myVar1))
console.log("typeof myVar2: "+typeof(myVar2))
</script>
<script>
function printMyName(){
let name = prompt("Hello whats your name: ");
document.getElementById("nameOfUser").innerHTML = "Hello! Welcom " + name;
}
</script>
Javascript Variables Exercise
Given the existing code below, can you write some code so that their values are switched around?
var a = "3";
var b = "8";
So that the variable a holds the value "8".
And the variable b holds the value "3".
When the code is run, it should output:
a is 8
b is 3
Do NOT change any of the existing code.
You are NOT allowed to type any numbers.
You should NOT redeclare the variables a and b.
Hint: Use this code playground to run your code and see if it matches your expectations.
Hint: The solution is just 3 lines of code.
<script>
//Code of
function lenCharacters(){
let text = document.getElementById("userInputText");
const max = 150;
//Using length
document.getElementById("results").innerHTML = ("Count: "+ text.value.length +
" Left: -"+ (max - text.value.length) + " (max=150)"
)
}
</script>
Using toUpperCase, toLowerCase
<script>
//Code of
function capitalize(){
let name = prompt("Type your name: ");
let nameUppercase = name.toUpperCase();
let nameLowercase = name.toLowerCase();
let nameCapitalice = name.toUpperCase().slice(0,1) + name.toLowerCase().slice(1,);
alert(
"Input: " + name + "\n\n"+
"name.toUpperCase():" + name.toUpperCase() + "\n"+
"name.toLowerCase():" + name.toLowerCase() + "\n"+
"Capitalice name:" + name.toUpperCase().slice(0,1) + name.toLowerCase().slice(1,)
)
}
</script>
Fórmula Human Age = (dogAge -2) *4 +1
<script>
//Code of
function getHumanAge(){
let dogAgeText = document.getElementById("dogAge");
let dogAge = Number(dogAgeText.value.slice(9,));
if (typeof(dogAge) !== typeof(1)) {
dogAge = Number(dogAgeText.value);
}
let humanAgeText = document.getElementById("humanAge");
let humanAge;
if (typeof(dogAge) == typeof(1)) {
if (dogAge > 0) {
humanAge = (Number(dogAge) -2) * 4 + 1;
}else{
humanAge = 0;
};
}else{
humanAge = 0;
};
if (humanAge < 0) {humanAge = humanAge*-1;};
humanAgeText.value = "Human Age: "+ humanAge;
dogAgeText.value = "Dog Age: "+ dogAge;
alert(
"Human Age aprox is: " + humanAge + "\n\n"
);
}
</script>