javaScript - Set

Set Methods

중복 X, 순서 X

new Set()	Creates a new Set
add()	Adds a new element to the Set
delete()	Removes an element from a Set
has()	Returns true if a value exists in the Set
forEach()	Invokes a callback for each element in the Set
values()	Returns an iterator with all the values in a Set
size(Property)	Returns the number of elements in a Set

 

 

 

new Set()

const letters = new Set(["a","b","c"]);

// Create a Set
const letters = new Set();

// Add Values to the Set
letters.add("a");
letters.add("b");
letters.add("c");

 

 

 

add()

<p id="demo"></p>

<script>
// Create a Set
const letters = new Set();

// Add values to the Set
letters.add("a");
letters.add("b");
letters.add("c");
letters.add("c");
letters.add("c");
letters.add("c");
letters.add("c");
letters.add("c");

// Display set.size
document.getElementById("demo").innerHTML = letters.size;
</script>

3

 

 

 

forEach()

<p id="demo"></p>

<script>
// Create a Set
const letters = new Set(["a","b","c"]);

// List all Elements
let text = "";
letters.forEach (function(value) {
  text += value + "<br>";
})

document.getElementById("demo").innerHTML = text;
</script>

a
b
c

 

 

 

 

 

 

 

values()

<p id="demo"></p>

<script>
// Create a Set
const letters = new Set(["a","b","c"]);

// List all Elements
let text = "";
for (const x of letters.values()) {
  text += x + "<br>";
}

document.getElementById("demo").innerHTML = text;
</script>

a
b
c