How Excel prevents spaces from being entered

In the Excel cell, we can prohibit the entry of spaces, there are three cases, respectively, as follows:

The method used is: "Data" → "validity", in the pop-up dialog box, the Settings tab, the validity condition select "Custom", and then, in the formula below it, enter the following three kinds of cases respectively.

First, the prohibition before and after and the middle cannot enter the space

The formula is as follows:

COUNTIF (A1, "* *") =0

Note that when Countif (A1, "* * *") =1, the space is allowed to be entered.

Second, prohibit in the first place cannot enter the space

The formula is:

=countif (A1, "*") =0

Third, do not allow the last one to enter a space

The formula is:

=countif (A1, "*") =0