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CanvasRenderingContext2D.setLineDash()

The CanvasRenderingContext2D.setLineDash() method of the Canvas 2D API sets the line dash pattern.

Syntax

void ctx.setLineDash(segments);

Parameters

segments
An Array. A list of numbers that specifies distances to alternately draw a line and a gap (in coordinate space units). If the number of elements in the array is odd, the elements of the array get copied and concatenated. For example, [5, 15, 25] will become [5, 15, 25, 5, 15, 25].

Examples

Using the setLineDash method

This is just a simple code snippet which uses the setLineDash method to draw a dashed line.

HTML

<canvas id="canvas"></canvas>

JavaScript

var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");

ctx.setLineDash([5, 15]);

ctx.beginPath();
ctx.moveTo(0,100);
ctx.lineTo(400, 100);
ctx.stroke();

Edit the code below and see your changes update live in the canvas:

Playable code
<canvas id="canvas" width="400" height="200" class="playable-canvas"></canvas>
<div class="playable-buttons">
  <input id="edit" type="button" value="Edit" />
  <input id="reset" type="button" value="Reset" />
</div>
<textarea id="code" class="playable-code">
ctx.setLineDash([5, 15]);
ctx.beginPath();
ctx.moveTo(0,100);
ctx.lineTo(400, 100);
ctx.stroke();</textarea>
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
var textarea = document.getElementById("code");
var reset = document.getElementById("reset");
var edit = document.getElementById("edit");
var code = textarea.value;

function drawCanvas() {
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  eval(textarea.value);
}

reset.addEventListener("click", function() {
  textarea.value = code;
  drawCanvas();
});

edit.addEventListener("click", function() {
  textarea.focus();
})

textarea.addEventListener("input", drawCanvas);
window.addEventListener("load", drawCanvas);

Specifications

Specification Status Comment
WHATWG HTML Living Standard
The definition of 'CanvasRenderingContext2D.setLineDash' in that specification.
Living Standard  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) 27 (27) 11 (Yes) (Yes)
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) 27.0 (27) (Yes) (Yes) (Yes)

Gecko-specific notes

  • Starting with Gecko 7.0 (Firefox 7.0 / Thunderbird 7.0 / SeaMonkey 2.4), the non-standard and deprecated property mozDash has been implemented to set and get a dash list. This property will be deprecated and removed in the future, see bug 931643. Use setLineDash() instead.

WebKit-specific notes

  • In WebKit-based browsers (e.g. Safari), the non-standard and deprecated property webkitLineDash is implemented besides this method. Use setLineDash() instead.

See also

Document Tags and Contributors

 Contributors to this page: fscholz
 Last updated by: fscholz,