Node Programming Examples

ES6 for-of Loop

node

'use strict' 
var roles = new Map([ 
   ['r1', 'User'], 
   ['r2', 'Guest'], 
   ['r3', 'Admin'], 
]);
for(let r of roles.entries()) 
console.log(`${r[0]}: ${r[1]}`);

ES6 Map Method values

node

var myMap = new Map(); 
myMap.set("id", "Admin"); 
myMap.set("pass", "admin@123"); 

var itr = myMap.values(); 
console.log(itr.next().value); 
console.log(itr.next().value);

ES6 Map Method keys

node

var myMap = new Map(); 
myMap.set("id", "admin"); 
myMap.set("pass", "admin@123"); 

var itr = myMap.keys(); 
console.log(itr.next().value); 
console.log(itr.next().value);

ES6 Map Method forEach

node

function userdetails(key,value) { 
   console.log("m[" + key + "] = " + value); 
}  
var myMap = new Map(); 
myMap.set("id", "admin"); 
myMap.set("pass", "admin@123"); 
myMap.forEach(userdetails);

ES6 Map Method entries()

node

var myMap = new Map(); 
myMap.set("id", "admin"); 
myMap.set("pass", "admin@123"); 

var itr = myMap.entries(); 
console.log(itr.next().value); 
console.log(itr.next().value);

ES6 Map Method clear()

node

var myMap = new Map(); 
myMap.set("bar", "baz"); 
console.log(myMap.size); 

myMap.clear(); 
console.log(myMap.size)

ES6 Map Method delete(key)

node

var myMap = new Map(); 
myMap.set("id", "admin"); 
myMap.set("pass", "admin@123"); 
console.log(myMap.has("id")); 

myMap.delete("id"); 
console.log(myMap.has("id"));

ES6 Collections Map Operation Example2

node

var roles = new Map([ 
   ['r1', 'User'], 
   ['r2', 'Guest'], 
   ['r3', 'Admin'], 
]);  
console.log(`value of key r1 before set(): ${roles.get('r1')}`) 
roles.set('r1','superUser') 
console.log(`value of key r1 after set(): ${roles.get('r1')}`)

ES6 Collections Map operations

node

var roles = new Map([ 
   ['r1', 'User'], 
   ['r2', 'Guest'], 
   ['r3', 'Admin'], 
]);  
console.log(roles.get('r2'))

ES6 Collections Example2

node

var roles = new Map(); 
roles.set('r1', 'User') 
.set('r2', 'Guest') 
.set('r3', 'Admin'); 
console.log(roles.has('r1'))

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