Dynamically add attributes to objects

 let form1={}
            for (var key in this.formInline) {
                if (
                    this.formInline[key] != null ||
                    this.formInline[key] != "" ||
                    this.formInline[key] != "0"
                ) {
                    form1[key]=this.formInline[key]
                }
            }

If your add is always prompted ...undifined, It must have been forgotten form1 The definition declares that the variable is an object .

There are many ways to solve a problem ： Also available , Useful object attributes to another object

var form = { ...this.formInline };
            for (var key in form) {
                if (
                    this.formInline[key] == null ||
                    this.formInline[key] == "" ||
                    this.formInline[key] == "0"
                ) {
                    delete form[key];
                }
            }