[Vuejs]-How to pass a variable by prop and not allow child to change it ( vue 2 )

You can clone the prop value, with these methods:

1. If the value is a simple data type (string, boolean, number):

this.mensagem = JSON.parse(JSON.stringify(this.mensagemEdit));

2. If the value is a simple object:

this.mensagem = Object.assign({}, this.mensagemEdit);

3. For more complex values (array of objects, nested objects) I suggest using lodash:

import { cloneDeep } from "lodash"

this.mensagem = cloneDeep(this.mensagemEdit);