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If any properties already exist on the <code>SimpleMap</code>, they will be overwritten.</p> </li> </ol> </div> <div class="returns"> <h3 class="returns-title">Returns</h3> <p> <code>{can.SimpleMap}</code>: <p>this SimpleMap, for chaining</p> </p> </div> </div> <section class="body"> <h2>Use</h2> <p><code>attr</code> gets or sets properties on the <code>SimpleMap</code> it's called on. Here's a tour through how all of its forms work:</p> <pre><code>var map = new SimpleMap({ age: 29 }); // get a property: foo.attr('age'); // 29 // set a property: foo.attr('age', 30); foo.attr('age'); // 30 // set and merge multiple properties: foo.attr({ first: 'Kevin', last: 'Phillips' }); foo.attr('age'); // 30 foo.attr('first'); // 'Kevin' foo.attr('last'); // 'Phillips' </code></pre> <p>When properties are changed using attr, the <code>SimpleMap</code> will emit events. Events can be listened to using <a href="can-event.on.html" title="can-event.on">on</a> or <a href="can-event.bind.html" title="can-event.bind">bind</a>.</p> <pre><code>var map = new SimpleMap({ age: 29 }); map.on('age', function(ev, newVal, oldVal) { newVal; // 30 oldVal; // 29 }); map.attr('age', 30); </code></pre> </section> <script type="text/javascript"> var docObject = {"src":{"path":"node_modules/can-simple-map/docs/prototype.attr.md"},"description":"Get or set properties on a SimpleMap. \n","title":"attr","name":"can-simple-map.prototype.attr","type":"function","parent":"can-simple-map.prototype","order":0,"signatures":[{"code":"map.attr(key)","description":"\n\nReads a property from this `SimpleMap`.\n","params":[{"types":[{"type":"String"}],"name":"key","description":"the property to read"}],"returns":{"types":[{"type":"*"}],"description":"the value assigned to _key_.\n"}},{"code":"map.attr(key, value)","description":"\n\nAssigns _value_ to a property on this `SimpleMap` called _key_.\n","params":[{"types":[{"type":"String"}],"name":"key","description":"the property to set"},{"types":[{"type":"*"}],"name":"the","description":"value to assign to _key_."}],"returns":{"types":[{"type":"can.SimpleMap"}],"description":"this SimpleMap, for chaining\n"}},{"code":"map.attr(obj)","description":"\n\nAssigns each value in _obj_ to a property on this `SimpleMap` named after the\ncorresponding key in _obj_, effectively merging _obj_ into the SimpleMap.\n","params":[{"types":[{"type":"Object","options":[]}],"name":"obj","description":"a collection of key-value pairs to set.\nIf any properties already exist on the `SimpleMap`, they will be overwritten.\n"}],"returns":{"types":[{"type":"can.SimpleMap"}],"description":"this SimpleMap, for chaining\n"}}],"_curReturn":{"types":[{"type":"can.SimpleMap"}],"description":"this SimpleMap, for chaining\n"},"_curParam":{"types":[{"type":"Object","options":[]}],"name":"obj","description":"a collection of key-value pairs to set.\nIf any properties already exist on the `SimpleMap`, they will be overwritten.\n"},"comment":" ","pathToRoot":".."}; </script> </article> <footer><p>CanJS is part of <a href="http://donejs.com" target="_blank">DoneJS</a>. 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