[circular array] JS method collection of circular array

One 、forEach loop

notes ： No, return Return value , And can't use break Out of the loop .

let arrlist = ['123','456','789'];

arrlist.forEach(function (value, index) {
    
   //value It's every item ,index It's the index 
    console.log(value,index);
});

Two 、for loop

notes ： This is the most basic way of circulation , You can use return End .

for(var i = 0;i < 10; i++){
    
    console.log(i)   // in every particular 
}

3、 ... and 、map loop

notes ： Map the original array into a new array , The original array will not be manipulated , Return a new array . Support return return .

let arrlist = ['111','222','333'];
arrlist.map(function(value,index){
    
	//value in every particular ,index Indexes 
	console.log(value,index);
});

Four 、for of loop

notes ： yes ES6 New loop method . You can respond to break、continue and return End . Support array , Class array objects are also supported .

let arrlist = ['111','222','333'];
for(let item of arrlist){
    
console.log(item); //item Refers to each item of the array .
}
// Output  '111' '222' '333'

Ongoing update ~