js set map code example

Example 1: append to map javascript

var myMap = {};

myMap[newKey] = newValue;

// ...


// Another method

var myMap = new Map()
myMap.set("key0","value")
// ...
myMap.has("key1"); // evaluates to false, assuming key1 wasn't set

Example 2: set in javascript

let mySet = new Set()

mySet.add(1)           // Set [ 1 ]
mySet.add(5)           // Set [ 1, 5 ]
mySet.add(5)           // Set [ 1, 5 ]
mySet.add('some text') // Set [ 1, 5, 'some text' ]
let o = {a: 1, b: 2}
mySet.add(o)

mySet.add({a: 1, b: 2})   // o is referencing a different object, so this is okay

mySet.has(1)              // true
mySet.has(3)              // false, since 3 has not been added to the set
mySet.has(5)              // true
mySet.has(Math.sqrt(25))  // true
mySet.has('Some Text'.toLowerCase()) // true
mySet.has(o)       // true

mySet.size         // 5

mySet.delete(5)    // removes 5 from the set
mySet.has(5)       // false, 5 has been removed

mySet.size         // 4, since we just removed one value

console.log(mySet)
// logs Set(4) [ 1, "some text", {…}, {…} ] in Firefox
// logs Set(4) { 1, "some text", {…}, {…} } in Chrome

Example 3: new map js

let utilisateurs = new Map()

utilisateurs.set('Mark Zuckerberg' ,{
    email: '[email protected]',
    poste: 'PDG',
})

utilisateurs.set ('bill Gates',{
    email: '[email protected]' ,
    poste : 'sauver le monde' ,

})
    
console.log(utilisateurs);

Example 4: map in javascript

['elem', 'another', 'name'].map((value, index, originalArray) => { 
  console.log(.....)
});