vuejs copying data object and removing property will remove the property from original object as well
You need to take a copy of your data by cloning it. There are various ways of cloning the data, I would recommend using lodash's function, cloneDeep
postDataCopy = _.cloneDeep(postData)
Then you can modify postDataCopy as you like without modifying the original.
this is because in javascript objects are copied-by-reference which means though you are changing postData which actually is referencing to original address that holds the data i.e. rows. you can do this
postData = JSON.parse(JSON.stringify(rows))
You need to make a copy of your referenced variable.
// ES6let copiedObject = Object.assign({}, originalObject)