JavaScript slice (), splice (), split (), substring (), substr () use method _javascript tips

1.slice ();

Both array and string objects have

Slice in Array (I,[j])

I is the index value that starts the interception, and the negative number represents the index value from the end, minus 1 is the first element.
J is the ending index value, and the default is to get all elements from I to the end

Parameter return:
Returns an array of index values from I to J, and the original array does not change

Slice in string (I,[j])

Parameter description:
I is the index value that starts the interception, and the negative number represents the index value from the end, minus 1 is the first character
J is the ending index value, and the default is to get all characters from I to the end

2.splice ()

There is a method in array that adds/deletes items to/from an array, and then returns the deleted item. This method will change the original array

Splice (INDEX,HOWMANY,ITEM1,ITEMX)

Index: Required. Integer that stipulates where to add/remove items, and use negative numbers to specify the position from the end of the array.

Howmany: Required. The number of items to delete. If set to 0, the item is not deleted.

ITEM1...ITEMX: Optional. The new item to add to the array.

The return value array contains a new array of deleted items, if any.

3.split ()

Split in string (Separator,howmany)

Separator: Required. A string or regular expression that splits the Stringobject from the place specified by the parameter.

Howmany: Optional. This parameter specifies the maximum length of the array to return. If this argument is set, the returned substring will not be more than the array specified by this parameter. If this argument is not set, the entire string is split, regardless of its length.

return value

An array of strings. The array is created by splitting the string stringobject into substrings at the boundary specified by separator. The string of the returned array does not contain separator itself

However, if separator is a regular expression that contains a subexpression, the returned array includes a string that matches the subexpression (but does not include text that matches the entire regular expression)

The opposite effect of the jion () function

4.substring ()

Substring in string (start,stop)

Start: Represents the starting position of the substring,

Stop: Indicates the end result.

Note: The second argument should be greater than the first argument. If the first argument is greater than the second argument, the substring method automatically replaces the position of the two parameters.

5.substr ()

In string, substr (start,length);

Start: The starting position of the substring,

Length: The lengths of substrings.

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