How to set font size in jQuery_jquery

First get the font size and process it.

Save the modified value.

The slice() method returns selected elements from an existing array.
arrayObject.slice(start,end).
start Required. Specifies where to start the selection. If negative, it specifies the position from the end of the array. That is, -1 refers to the last element, -2 refers to the second to last element, and so on.

end Optional. Specifies where to end the selection. This parameter is the array index at the end of the array fragment. If this parameter is not specified, the split array contains all elements from start to the end of the array. If this parameter is negative, it specifies the elements starting from the end of the array.

The jQuery code is as follows: