Core Code
Core Code Modern Dev Handbook

Proxy Validation Example

Validate property values using Proxy.

Preview

Code

<script>
let user = {};

let proxy = new Proxy(user,{
  set(obj,prop,value){
    if(prop === "age" && value < 0){
      throw new Error("Invalid age");
    }
    obj[prop] = value;
    return true;
  }
});

proxy.age = 25;
console.log(proxy.age);
</script>

More JS Meta & Proxy Examples (7)

example Basic Proxy Example open example example Proxy Set Trap open example example Proxy Default Value open example example Reflect Get Example open example example Reflect Set Example open example example Proxy Logging Example open example example Proxy Delete Trap open example