How can I use regular and bold in a single String?

I have a String that consists of a constant part and a variable part. I want the variable to be formatted using a regular font within the text paragraph, whereas I want the constant part to be bold.

This is my code:

String cc_cust_name = request.getParameter("CC_CUST_NAME");    
document.add(new Paragraph(" NAME  " + cc_cust_name, fontsmallbold));

My code for a cell in a table looks like this:

cell1 = new PdfPCell(new Phrase("Date of Birth" + cc_cust_dob ,fontsmallbold));

In both cases, the first part (" NAME " and "Date of Birth") should be bold and the variable part (cc_cust_name and cc_cust_dob) should be regular.

Right now you are creating a Paragraph using a single font: fontsmallbold. You want to create a Paragraph that uses two different fonts:

Font regular = new Font(FontFamily.HELVETICA, 12);
Font bold = Font font = new Font(FontFamily.HELVETICA, 12, Font.BOLD);
Paragraph p = new Paragraph("NAME: ", bold);
p.add(new Chunk(CC_CUST_NAME, regular));

As you can see, we create a Paragraph with content "NAME: " that uses font bold. Then we add a Chunk to the Paragraph with CC_CUST_NAME in font regular.

See also How to set two different colors for a single string in itext and Applying color to Strings in Paragraph using Itext which are two questions that address the same topic.

You can also use this in the context of a PdfPCell in which case you create a Phrase that uses two fonts:

Font regular = new Font(FontFamily.HELVETICA, 12);
Font bold = Font font = new Font(FontFamily.HELVETICA, 12, Font.BOLD);
Phrase p = new Phrase("NAME: ", bold);
p.add(new Chunk(CC_CUST_NAME, regular));
PdfPCell cell = new PdfPCell(p);