How to delete specified elements from js array

How to delete specified elements from js arrays: First define a function for the js array object to find the position of the specified element in the array, that is, the index; then use the corresponding function through the obtained index of the specified element to delete the specified element.

First, you can define a function for the JS array object to find the position of the specified element in the array, that is, the index. The code is:

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Array.prototype.indexOf = function(val) { 
for (var i = 0; i < this.length; i++) { 
if (this[i] == val) return i; 
} 
return -1; 
};

Then use the index of the element to get the index, and use the js array's own inherent function to delete the element:

The code is:

Array.prototype.remove = function(val) { 
var index = this.indexOf(val); 
if (index > -1) { 
this.splice(index, 1); 
} 
};

In this way, such a function is constructed. For example, I have an array:

var emp = ['abs','dsf','sdf','fd']

If we want to delete the 'fd' in it, we can use:

emp.remove('fd');

Delete an item of the array

splice(index,len,[item]) Note: This method will change the original array.

splice has 3 parameters, it can also be used to replace/delete/add one or several values ​​in the array

index: array starting subscript len: replacement/delete length item :Replacement value, if the delete operation is performed, the item will be empty

For example: arr = ['a','b','c','d']

Delete

//删除起始下标为1，长度为1的一个值(len设置1，如果为0，则数组不变) 
var arr = ['a','b','c','d']; 
arr.splice(1,1); 
console.log(arr); 
//['a','c','d']; 
 
 
//删除起始下标为1，长度为2的一个值(len设置2) 
var arr2 = ['a','b','c','d'] 
arr2.splice(1,2); 
console.log(arr2); 
//['a','d']

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