Now I will share with you a JS method to delete an element in an array. It has a good reference value and I hope it will be helpful to everyone.
Delete an element specified in the array
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:
Array.prototype.indexOf = function(val) {
for (var i = 0; i < this.length; i++) {
if (this[i] == val) return i;
}
return -1;
};Then use to get the index of this element, and use the js array's own inherent function to delete this element:
The code is:
Array.prototype.remove = function(val) {
var index = this.indexOf(val);
if (index > -1) {
this.splice(index, 1);
}
};This way Constructed such a function, 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');
Deleted array An item of
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']
Replace
//替换起始下标为1，长度为1的一个值为‘ttt'，len设置的1 var arr = ['a','b','c','d']; arr.splice(1,1,'ttt'); console.log(arr); //['a','ttt','c','d'] var arr2 = ['a','b','c','d']; arr2.splice(1,2,'ttt'); console.log(arr2); //['a','ttt','d'] 替换起始下标为1，长度为2的两个值为‘ttt'，len设置的1
Add----len is set to 0, item is the added value
var arr = ['a','b','c','d']; arr.splice(1,0,'ttt'); console.log(arr); //['a','ttt','b','c','d'] 表示在下标为1处添加一项'ttt'<span style="font-size:14px;font-family:Arial, Helvetica, sans-serif;background-color:rgb(255,255,255);"> </span>
After the delete method deletes the elements in the array, it will set the subscripted value to undefined, and the length of the array will not change.
var arr = ['a','b','c','d']; delete arr[1]; arr; //["a", undefined × 1, "c", "d"] 中间出现两个逗号，数组长度不变，有一项为undefined
The above is what I compiled for everyone. I hope it will be helpful to everyone in the future. .
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