The Apex String method format() is my preferred way to build up a string in the absence of something like a .NET StringBuilder.
The help docs are currently a bit lightweight on detail:
Treat the current string as a pattern that should be used for substitution in the same manner as apex:outputText.
The apex:outputText documentation says:
The value attribute supports the same syntax as the MessageFormat class in Java. See the MessageFormat class JavaDocs for more information.
The syntax in Eclipse appears as: String.format(String pString, List
Usage is a format string followed by the substitution arguments as an array.
String formattedString = String.format('Hello {0}, shall we play a {1}?', new String[]{'David', 'game'}); System.debug(formattedString);
Apex String.format and escaped single quotes
String.format(); can be a bit fiddly when it comes to outputting single quotes. A solitary escaped single quote will be lost from the output and prevent further string substitutions.
For Example:
String formattedString = String.format('Hello {0}, shall we play a \'{1}\'?', new String[]{'David', 'game'}); System.debug(formattedString);
Will result in:
Hello David, shall we play a {1}?
The java.text.MessageFormat documentation says:
Within a String, "''" represents a single quote. A QuotedString can contain arbitrary characters except single quotes; the surrounding single quotes are removed.
Example with the escaping to produce the expected output:
String formattedString = String.format('Hello {0}, shall we play a \'\'{1}\'\'?', new String[]{'David', 'game'}); System.debug(formattedString);
Will result in:
Hello David, shall we play a 'game'?
See Also: