Every (), map (), forearch () methods. There are objects in the array

every（） Method
This is an array and an object ：
Method is used to check whether all elements of the array meet the specified conditions （ Provide... Through functions ）.
every() Method uses the specified function to detect all elements in the array ：

If an element in the array is detected to be unsatisfied , The entire expression is returned false , And the remaining elements are no longer detected .
If all the elements satisfy this condition , Then return to true.
Be careful ： every() Empty arrays are not detected .
Be careful ： every() It doesn't change the original array .

<template>
<button  @click="chooseButton(index)" :class="item.myShow===true?'collectTwo' : 'my_choose'" ></button>
</template>
export default{
    
		data（）{
    
		return{
    
			collestList:[
				{
    
					myshow:false
				},
				{
    
					myshow:false
				},
				{
    
					myshow:false
				}
			]
		}
	}
method：{
    
		//  Selected items 
		chooseButton:function(res){
    
			//  Determine whether all are selected 
		    let  myselse = 	this.collestList.every(item=>{
    if (item.myShow==true) return true })
			console.log(myselse)// Output is false
		},
	}
}

map() Method
effect ： Process the array by specifying a function , And return the processed results in the form of a new array

Be careful ： It doesn't change the original array , Just return the processed results in the form of a new array

var users = [
  {
    name: " Zhang Hanyun ", "email": "[email protected]"},
  {
    name: " Jiang Yiyan ",   "email": "[email protected]"},
  {
    name: " Li Xiaolu ",  "email": "[email protected]"}
];

var emails = users.map(function (user) {
     return user.email; });
console.log(emails);
//["[email protected]", "[email protected]", "[email protected]"]

forEach() Method
forEach() Method is used to call each element of an array , And pass the element to the callback function .
Be careful : forEach() Callbacks are not performed for empty arrays .

this.collestList.forEach((value , index) => {
    
								/// This is collestList Add inside myShow:false  Field of 
								value['myShow1'] = false 
								
							})

/// It's like this 
			collestList:[
				{
    
					myshow:false,
					myshow1:false
				},
				{
    
					myshow:false,
					myshow1:false
				},
				{
    
					myshow:false,
					myshow1:false
				}
			]