New Post: converting Text to Numeric form

Unless you use setCellValueExplicit(), then PHPExcel uses a value binder to identify the datatype that you are setting in the cell.

By default, this is PHPExcel_Cell_DefaultValueBinder, which performs a very simplistic check on whether the PHP datatype is Null or Boolean, or a numeric value or a string. A value such as 37.7% is a PHP string, so will be treated as a string.

There is also an advanced value binder (PHPExcel_Cell_AdvancedValueBinder) that can perform much more sophisticated checks, and is capable of identifying strings containing basic date formats and converting them to an Excel serialized datetime, and setting a number format mask accordingly. It can also detect currency values, fractions, and (most importantly) percentages.

If you pass a string value like 37.7% through the advanced value binder, it will divide the numeric part by 100, and set the number format mask to a percentage mask, in exactly the same way as the MS Excel GUI.

To enable the advanced value binder, call

PHPExcel_Cell::setValueBinder( new PHPExcel_Cell_AdvancedValueBinder() );

before instantiating your PHPExcel object.

You can find an example of advanced binder usage in /Examples/29advancedvaluebinder.php