The stack.keys() method makes an array of strings as an argument and returns the stack generator.
Syntax:
stack.keys([keys])
Parameters: This method accepts a single parameter as mentioned above and described below.
- domain: This parameter holds an array of strings as key arguments.
Return Value: This method returns the stack generator.
Example:
HTML
<!DOCTYPE html> <html> <head>     <meta charset="utf-8">     <script src=     </script> </head>   <body>     <h1 style="text-align: center; color: green;">         neveropen     </h1>     <center>         <canvas id="gfg" width="200" height="200">         </canvas>     </center>       <script>         var data = [               {a: 3840, b: 1920, c: 960, d: 400},               {a: 1600, b: 1440, c: 960, d: 400},               {a: 640, b: 960, c: 640, d: 400},               {a: 320, b: 480, c: 640, d: 400}             ];           var stackGen = d3.stack()             // Defining keys             .keys(["a", "b", "c", "d"])           var stack = stackGen(data);                   console.log(stack);           for (i = 0; i < 4; i++) {               // Displaying keys             console.log(stack[i].key);           }     </script> </body> </html> |
Output:
