vm.$set()

vm.$set( keypath, value )

• Arguments:

  • {String} keypath
  • {*} value

• Usage:

  Set a data value on the Vue instance given a valid keypath. In most cases you should prefer setting properties using plain object syntax, e.g. vm.a.b = 123. This method is only needed in two scenarios:

  1. When you have a keypath string and want to dynamically set the value using that keypath.

  2. When you want to set a property that doesn’t exist.

  If the path doesn’t exist it will be recursively created and made reactive. If a new root-level reactive property is created due to a $set call, the Vue instance will be forced into a “digest cycle”, during which all its watchers are re-evaluated.

• Example:

  var vm = new Vue({
    data: {
      a: {
        b: 1
      }
    }
  })
  
  // set an existing path
  vm.$set('a.b', 2)
  vm.a.b // -> 2
  
  // set a non-existent path, will force digest
  vm.$set('c', 3)
  vm.c // ->

• See also: Reactivity in Depth