- alert()
- prompt()
() means to execute function.
So, this bracket mean 'calling a function', so I can call aa function.
() must be included to use function.
That things inside brackets are called arguments(인수).
console.log("Hello", "How are you");
<!--script.js--><!DOCTYPE html>
<html>
<head>
<title>Javascript</title>
<link rel="stylesheet" type="text/css" href="">
</head>
<body>
<h1> waiting Javasscript in HTML</h1>
<script type="text/javascript" src="script.js">
</script>
</body>
</html>
JAVASCRIPT FUNCTIONS
- var a = function name() {}
- function name() {}
- return
- "< !-- () => (new in ECMAScript 6) -->"
function sayHello(){
console.log("Hello");
}<!--script.js-->And then save and refresh, but nothing happened.
function sayHello(){
console.log("Hello");
}
sayHello();We should call function. So say 'sayHello()'. Now refresh.
I get hello.
The second way to make function is called 'function expression'.
function sayHello(){
console.log("Hello");
}
sayHello();
var sayBye =function(){
console.log("Bye");
}
sayBye();
One thing you may have noticed here, is that we're assigning this function to the 'sayBye' variable, but what is the name of the function.
I mean here clearly function's name is 'sayHello', but here we're just assigning to the variable.
I mean, technically the function doesn't have a name and this is called an 'anonymous function'(in here).
function sing(){
console.log("AHHHHH");
console.log("TEEEEE");
}
sing();
If you want to change the song, I can say "Laaa deee daaa", "helloooooooo", "backstreets back alright"
function sing(song){
console.log(song);
}
sing("Laaa deee daaa");
sing("helloooooooo");
sing("backstreets back alright");
.
function multiply(a, b){
return a * b;
}'return': reads the line and then exits.
function multiply(a, b){
if(a > 10 || b >10){
return "that's too hard";
} else{
return a*b;
}
}
function multiply(a, b){
if(a > 10 || b >10){
return "that's too hard";
} else{
return a*b;
}
return a*b;
}I added return a*b; but it doesn't work.
Because there's return in if-else.
function a = multiply(a, b){
if(a > 10 || b >10){
return "that's too hard";
} else{
return a*b;
}
return a*b;
}.
function a = multiply(a, b){
return a*b;
}
alert(multiply(3,4));
function multiply(a, b){
return a*b;
}
var total = multiply(4,5);
alert(total);
parameters(매개변수): a, b
arguments(인수): 4, 5
