d3.js enter example

d3-js-enter.js

//so there's two divs on the page for this to select
d3.select('body')
    .selectAll('div')
    .data(["hello","there","world"])
    //this will map "hello" and "there" to the only two divs
    .html(function(d){return d;})
    //but theres 3 pieces of data...?
    //this is why d3 has the enter() function
    //think of it as "withTheLeftOverDataAfterMapping()" instead of "enter()"
    .enter()
        //so now we can do something with the leftover data,
        //how about create another div?
        .append('div')
        .html(function(d){return d;});