How to print only the value(s) in the display?
let room1 = new Map();
room1.set("candles", 8)
room1.set("fridge", 1)
room1.set("washing machine", 3)
room1.set("chairs", 4)
room1.set("sofa", 2)
room1.set("jacuzzi", 6)
let text4 = "";
room1.forEach(function(key) {
text4 += key + "<br>"
});
document.getElementById("demo8").innerHTML = text4;<p id="demo8"></p>It's 2022. Forget forEach and use for...of. It gets key-value pairs when iterating over a Map:
let room1 = new Map();
room1.set("candles", 8)
room1.set("fridge", 1)
room1.set("washing machine", 3)
room1.set("chairs", 4)
room1.set("sofa", 2)
room1.set("jacuzzi", 6)
let text4 = "";
for(let [key,value] of room1) {
text4 += `${key} - ${value}<br>`; // this could be key+" - "+value+"<br>" of course
};
document.getElementById("demo8").innerHTML = text4;<p id="demo8"></p>1) For a better performance use for...of instead forEach:
for(let [key] of room1) {
text4 += key + "<br>";
};
2) Short code (spread syntax) to get the keys of your Map and convert to Array:
[...room1.keys()].forEach(function(key) {
text4 += key + "<br>"
});
3) The same of first solution but with Array.from(...) explicit:
Array.from(room1.keys()).forEach(function(key) {
text4 += key + "<br>"
});
4) Add the first parameter value to forEach function:
room1.forEach(function(value, key) {
text4 += key + "<br>"
});
Example:
let room1 = new Map();
room1.set("candles", 8)
room1.set("fridge", 1)
room1.set("washing machine", 3)
room1.set("chairs", 4)
room1.set("sofa", 2)
room1.set("jacuzzi", 6)
let display = document.getElementById("demo8");
for (let [key] of room1) {
display.innerHTML += key + "<br>";
};<p id="demo8"></p>You could get only the keys directly.
let rooms = new Map();
rooms.set("candles", 8)
rooms.set("fridge", 1)
rooms.set("washing machine", 3)
rooms.set("chairs", 4)
rooms.set("sofa", 2)
rooms.set("jacuzzi", 6)
console.log([...rooms.keys()]);