Basic

Flow Control流程控制

//For loop
for(let i=0;i<5;i++){
  console.log('hello');
}

//While loop
let i = 0;
While(i<5){
  console.log('Hello');
  i++;
}

//Do While loop
let i=0;
do{
  console.log('hi');
  i++;
} while (i<5);


//For...in 
const person = {name:'weili', age:35};
for(let key in person){
  console.log(key, person[key])
}

const colors = ['red','green','blue'];
for(let index in colors){
	console.log(colors[index]);
}

//For...of 
const colors = ['red','green','blue'];
for(let color of colors){
	console.log(color);
}

//if..else
if( 1 > 2 ){
  console.log('true');
}else{
  console.log('false');
}

//Switch...case
let role;
switch (role) {
  case 'guest':
    console.log('guest user');
    break;
  case 'admin':
    console.log('admin user');
    break;
  default:
    console.log('unkown user');
}

//Break and continue
break - get out of the loop altogether
continue - get out of current iteration and go to the next iteration

let i = 0;
while(i<=10){
	if(i==9) break;
	if(i==5) {i++;continue;}
	console.log(i);
}