D3.js in Action by Elijah Meeks

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Filter(), which returns an array whose elements satisfy a test you provide. filter() is a method of an array and accepts a function that iterates through the array with the variable you’ve named. In this function, you name that variable el, and the function runs a test on each value by testing on el. When that test evaluates true, the element is kept in our new array. 27, returns either the element or nothing (depending on if it satisfies the test), building a new array consisting only of the elements that do.

This may not seem too big a deal, but it’s something to remember when you’re trying to line up your shapes later on. Change the style parameters of the rectangle to the following: "fill:purple;stroke-width:5px;stroke:cornflowerblue;" Congratulations! ” SVG provides the capacity to write text as well as shapes. SVG text, though, doesn’t have the formatting support found in HTML elements, and so it’s primarily used for labels. If you do want to do basic formatting, you can nest elements in elements.

SVG drawing instructions for complex shapes, known as elements, are written a bit like the old LOGO programming language. You start at a point on a canvas and draw a line from that point to another. If you want it to curve, you can give the SVG drawing code coordinates on which to make that curve. 667,385. 8571429 But you’d almost never want to create SVG by manually writing drawing instructions like this. Instead, you’ll want to use D3 to do the drawing with a variety of helper functions, or rely on other SVG elements that represent simple shapes (known as geometric or graphical primitives) using more readable attributes.