ES6 数组some()和every()的使用及说明

/** 
 * 计算对象数组中每个电脑的扣件系统是否可用,大于16位操作系统表示可用,否则不可用
*/
var computers = [
    {name:"Apple",ram:8},
    {name:"IBM",ram:4},
    {name:"Acer",ram:32},
];
 var result= computers.every(function(computer){
   return computer.ram > 16
})
console.log(result)//false;
var some = computers.some(function(computer){
   return computer.ram > 16
})
console.log(some)//true;

/**
 * 假定有一个注册页面,判断所有Input内容的长度是否大于0
 * 
 */
function Field(value){
    this.value = value
}
// 在原型上定义方法
Field.prototype.validate = function(){
    return this.value.length > 0;
}
var username = new Field('2131');
var telephone  = new Field('8888888888888')
console.log(username.validate() && telephone.validate())//true
 
 
//二`:
var username = new Field('2131');
var telephone  = new Field('8888888888888')
let password  = new Field('');
//console.log(username.validate() && telephone.validate())//只要一个为空就为false
// 简化方式
var fields = [username, telephone,password];
console.log(fields)
var formIsValid = fields.every(function(field){
    return field.validate()
});
console.log(formIsValid)
 
if(formIsValid){
    //注册成功
}else{
    //给用户一个错误提醒
}

arr.方法名((item,index,arr)=>{
})

let arr=[1,2,3,4];
arr.forEach(function(value,index,arr){
//在这里进行相关操作
})

let potatos = [
  { id: '1001', weight: 50 },
  { id: '1002', weight: 80 },
  { id: '1003', weight: 120 },
  { id: '1004', weight: 40 },
  { id: '1005', weight: 110 },
  { id: '1006', weight: 60 }
]
  let w = potatos.map(function(potato) {
        return potato.weight
    })
 //在这里，potato.weight就是函数的返回值

let potatos = [
  { id: '1001', weight: 50 },
  { id: '1002', weight: 80 },
  { id: '1003', weight: 120 },
  { id: '1004', weight: 40 },
  { id: '1005', weight: 110 },
  { id: '1006', weight: 60 }
]
let bigPotatos=potatos.filter(potato=>potato.weight>=100)
//potato.weight>=100 就是返回值，为布尔值，如果为true，则当前遍历到potato就会作为新数组中的值

let potatos = [
  { id: '1001', weight: 50 },
  { id: '1002', weight: 80 },
  { id: '1003', weight: 120 },
  { id: '1004', weight: 40 },
  { id: '1005', weight: 110 },
  { id: '1006', weight: 60 }
]

let hasBig = potatos.some(potato => potato.weight >= 100)
// 只要返回值为true，则内部停止遍历，some返回值true，如果每次都返回false，则some返回值为false

let potatos = [
  { id: '1001', weight: 50 },
  { id: '1002', weight: 80 },
  { id: '1003', weight: 120 },
  { id: '1004', weight: 40 },
  { id: '1005', weight: 110 },
  { id: '1006', weight: 60 }
]

let hasBig = potatos.every(potato => potato.weight >= 100)
// 只要所有返回值为true，则every返回true，如果由一次返回false，则every返回值为false

let potatos = [
  { id: '1001', weight: 50 },
  { id: '1002', weight: 80 },
  { id: '1003', weight: 120 },
  { id: '1004', weight: 40 },
  { id: '1005', weight: 110 },
  { id: '1006', weight: 60 }
]

let bigPotato = potatos.find(potato => potato.weight >= 100) 
// 得到第一个符合条件的数据，返回给变量

let potatos = [
  { id: '1001', weight: 50 },
  { id: '1002', weight: 80 },
  { id: '1003', weight: 120 },
  { id: '1004', weight: 40 },
  { id: '1005', weight: 110 },
  { id: '1006', weight: 60 }
]

let bigPotato = potatos.findIndex(potato => potato.weight >= 100) 
// 得到第一个符合条件的数据的下标，返回给变量