'xxx{: }yyyformat(' ''xxxayyy'xxx{: }yyy {: 'xxxayyy -substitute string -pad to spaces (left aligns by default the real fun starts when we put something inside those curly brackets these are the formatting instructions the simplest examples start with colon followed by some layout instructions (we will see what comes in front of the colon in few slides time the number indicates how many spaces to allocate for the insertion and the letter that follows tells it what type ob object to expect "sstands for string