How to remove empty data from es6 array

Two methods: 1. Use for to find the element with an empty value, and use splice() to delete it. The syntax is "for(i=0;i

The operating environment of this tutorial: Windows 7 system, ECMAScript version 6, Dell G3 computer.

Two methods to remove empty data from es6 array

Method 1: Use for loop and splice() function

• Use a for loop to traverse the array

• Find the element with an empty value in the loop body

• According to the index of the element, use the splice() function to remove the element

Implementation code:

//数组去空值
    var arr1=["某某","",3,5,"color","",3,"某某","color",""]
    console.log(arr1)
  //拓展数组去空值的方法
    Array.prototype.removeEmpty=function () {
      for(var i=0;i<this.length;i++){
        if(this[i]==""||typeof(this[i])=="undefind"){
          this.splice(i,1);
          i--;
        }
      }
      return this;
    }
    var arr2=arr1.removeEmpty();

Method 2: Use the filter() function to filter the array and return non-empty elements

filter() function will call a callback function to filter the array elements and return all elements that meet the conditions (create a new array to return)

• You only need to set the qualifying condition to "not empty data"

How to write the function to set the filter condition

function f(value){
	return (value);
}

Use the filter() function to call a callback function f(value) to filter the array.

Implementation code:

//数组去空值
	
function f(v){
	return (v);
}
var arr1=["某某","",3,5,"color","",3,"某某","color",""]
console.log(arr1)
var arr2=arr1.filter(f);
console.log(arr2)

Description: filter() method

filter() method Creates a new array whose elements are checked by checking all elements in the specified array that meet the criteria.

Function: You can return the elements in the array that meet the specified conditions.

array.filter(function callbackfn(Value,index,array),thisValue)

function callbackfn(Value,index,array): A callback function, which cannot be omitted. It can accept up to three parameters:

• value: The value of the current array element, cannot be omitted.

• index: The numeric index of the current array element.

• array: The array object to which the current element belongs.

The return value is a new array containing all the values ​​for which the callback function returns true. If the callback function returns false for all elements of array , the length of the new array is 0.

Let’s learn more about it through an example: Return all even numbers

var a = [2,3,4,5,6,7,8];
function f (value) {
	if (value % 2 == 0) {
		return true;
	}else{
		 return false;
	}
}
var b = a.filter(f);
console.log(b);

Output result:

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