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The CanvasRenderingContext2D.getLineDash() method of the Canvas 2D API gets the current line dash pattern.


Array ctx.getLineDash();

Return value

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


Using the getLineDash method

This is just a simple code snippet which uses the getLineDash method.


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


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

ctx.setLineDash([5, 15]);
console.log(ctx.getLineDash()); // [5, 15]

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

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" />
<textarea id="code" class="playable-code">
ctx.setLineDash([5, 15]);
ctx.lineTo(400, 100);
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);

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

edit.addEventListener("click", function() {

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


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

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes122711 Yes Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes27 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 931389. Use getLineDash() instead.

WebKit-specific notes

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

See also


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最終更新者: fscholz,