let result = [1,2,3,4,5].reduce((prev, next, currIndex, ary)=>{
console.log(prev, next, currIndex, ary)
if(currIndex === ary.length - 1){
return (prev + next) / ary.length
}
return prev + next
}, 0)
console.log(result)
let total = [{price: 10}, {price: 20}, {price: 30}].reduce((prev, next, currIndex, ary)=>{
return prev + next.price
}, )
console.log(total)
let arr1 = [0,1,2,3,4];
let total2 = arr1.reduceRight((prev, next, currIndex, ary) =>{
return prev + next;
});
console.log(total2)
let fileterArr = [ { id: 1, text: 'aa', done: true }, { id: 2, text: 'bb', done: false },{ id: 3, text: 'cc', done: '' }];
let xinArr = fileterArr.filter(item=>item.done)
console.log(xinArr)
let NumberArr = [73,84,56, 22,100]
let newArr = NumberArr.filter(item => item>80)
let arr3 = [ 1, 2, 3, 4, 5, 6 ];
console.log(arr3.every( function( item, index, array ){
return item === 3;
}));
let arr4 = [ 1, 2, 3, 4, 5, 6 ];
console.log( arr4.some( function( item, index, array ){
return item === 3;
}));
let stu = [
{
name: '张三',
gender: '男',
age: 20
},
{
name: '王小毛',
gender: '男',
age: 20
},
{
name: '李四',
gender: '男',
age: 20
}
]
function getStu(element){
return element.name == '李四'
}
console.log(stu.find(getStu))
let stuObj = stu.find((element) => (element.name == '李四'))
console.log(stuObj)
console.log([1,2,3].findIndex(x => x == 2))
console.log([1,2,3].findIndex(x => x == 4));
for (let index of ['a', 'b'].keys()) {
console.log(index);
}
for (let item of ['a', 'b'].values()) {
console.log(item);
}
for (let [index, item] of ['a', 'b'].entries()) {
console.log(index, item);
}
console.log([1,2,3].includes(3))
function arg(){
console.log(Array.from(arguments))
console.log(eval(Array.from(arguments).join("+")))
}
arg(1, 2, 3);
let ary = Array.of(1,2,3)
console.log(ary)