问每次打印结果集的数据为3

EN

// a forEach loop takes an array and calls a function on each element in it
array.forEach((el, index, arr) => {
    // is this element a multiple of 3?
    if ((index + 1) % 3 === 0) {
        // If so, log it, as well as the 2 preceding elements
        console.log(arr[index-2], arr[index-1], el)

    // Otherwise, is this element the last one in the array, meaning there
    // wont be another tuple logging this element
    } else if (index === arr.length - 1) {
        // If so, how many elements are left, one or two?
        // log this many last elements to the console
        // I used a ternary in this case it is basically a shorthand if 
        // [expression] ? [if true] : [if false]
        arr.length % 3 === 1 ? console.log(arr[index]) : console.log(arr[index - 1], arr[index])
    }
})

let array = [1, 4, 5, 6, 7, 78, 3, 999, 544, 3, 3, 32233, 223, ];
array.map((search,index) => {

  if(index%3!==0){
     return;
  }

  let limit = index+3;
  
  // this part need when index almost at the end of the array
  if((index+3)>=array.length){
     limit =array.length;
  }
  console.log("chunks of data--->", array.slice(index,limit));
  //     };
});

var array = [1, 4, 5, 6, 7, 78, 3, 999, 544, 3, 3, 32233, 223, ];

var n = 3;
var chunk;

for (var i = 0; i < array.length; i += n) {
  chunk = array.slice(i, i + n);
  console.log(chunk);
}