How to write to file using fwrite?

    #include <QApplication>
    #include <newForm.h>
    int main(int argc, char *argv[]) {
    
        QApplication app(argc, argv);
        newForm *a = new newForm();
        a->show();
        return app.exec();
    }
Here is the newForm.h

    
    #include "newForm.h"
    #include <stdio.h>
    #include <stdlib.h>
    #include <QDebug>
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <errno.h>
    
    #define MAX 128
    int i, n = 2;
    
    char str[50], Name[50], Class[50], Grade[50], Section[50], Number[50], Total[50], var1[50], var2[50];
    FILE *fptr;
    int count = 0;
    
    newForm::newForm() {
        widget.setupUi(this);
        connect(widget.pushButton_1, SIGNAL(clicked()), this, SLOT(Load()));
        connect(widget.pushButton_2, SIGNAL(clicked()), this, SLOT(Update()));
    }
    
    void newForm::Load() {
        fptr = fopen("/root/Desktop/simple.conf", "r");
    
        if (fptr == NULL) {
            printf("Could not open file");
        }
        for (int i = 0; i < 10; i++) {
            if (EOF == fscanf(fptr, "%s", var1)) {
                break;
            }
    
            if (EOF == fscanf(fptr, "%s", var2)) {
                break;
            }
    
            if (strcmp(var2, "Name") == 0) {
                sprintf(Name, "%s", var1);
                widget.lineEdit_1->setText(QString::fromStdString(Name));
            }
            if (strcmp(var2, "Class") == 0) {
                sprintf(Class, "%s", var1);
                widget.lineEdit_2->setText(QString::fromStdString(Class));
            }
            if (strcmp(var2, "Section") == 0) {
                sprintf(Section, "%s", var1);
                widget.lineEdit_3->setText(QString::fromStdString(Section));
            }      
            if (strcmp(var2, "Number") == 0) {
                sprintf(Number, "%s", var1);
                widget.lineEdit_4->setText(QString::fromStdString(Number));
            } 
            if (strcmp(var2, "Total") == 0) {
                sprintf(Total, "%s", var1);
                widget.lineEdit_5->setText(QString::fromStdString(Total));
            }
        }
        fclose(fptr);
    }

#include <stdio.h>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <iostream>
#include <bits/stdc++.h>

#include <stdio.h>

const int StrSize = 49;
typedef char textStr[StrSize + 1];

void newForm::Update(){
    fptr = fopen("/root/Desktop/simple.conf","r" );
    textStr str,name,section,number,class1,total,grade,var1,var2;    
   
    strcpy(name,     widget.lineEdit_1->text().toLocal8Bit());
    strcpy(class1,   widget.lineEdit_2->text().toLocal8Bit());   
    strcpy(section, widget.lineEdit_3->text().toLocal8Bit());
    strcpy(number,  widget.lineEdit_4->text().toLocal8Bit());
    strcpy(total,   widget.lineEdit_5->text().toLocal8Bit());

    const char * text = NULL;
    for (int i = 0; i < 10; i++){
        if( EOF == fscanf(fptr, "%s", var1)){
            break;
        }

        if( EOF == fscanf(fptr, "%s", var2)){
            break;
        }
        const char * text = NULL;
        if(strcmp(var2,"Name") == 0){
           fwrite(name, sizeof(name) , sizeof(name) , fptr);
        }
        if(strcmp(var2,"Class") == 0){                      
            fwrite(class1, sizeof(class1) , sizeof(class1) , fptr);
        }if(strcmp(var2,"Name") == 0){
           fwrite(section, sizeof(section) , sizeof(section) , fptr);
        }
        if(strcmp(var2,"Section") == 0){                      
            fwrite(class1, sizeof(class1) , sizeof(class1) , fptr);
        }
        if(strcmp(var2,"Number") == 0){
            fwrite(grade, sizeof(grade) , sizeof(grade) , fptr);
        }
        if(strcmp(var2,"Total") == 0){
            fwrite(grade, sizeof(grade) , sizeof(grade) , fptr);
        }
        else if((strcmp(var2, "Name") != 0)  &&  (strcmp(var2, "Class") != 0)  &&  (strcmp(var2, "Grade") != 0) && strcmp(var2,"Number") !=0 && strcmp(var2,"Total") != 0) {
            fwrite(var1, sizeof(var1) , sizeof(var1) , fptr);
        }       
    }    
    fclose(fptr);

}

AAA		Name        
192.168.9.33	Class 
72.777		Number   
A10	Section          
100		Total        

AAA		Name          ----------------------->String/ 
192.168.9.33	Class ----------------------->I.p
72.777		Number    ----------------------->float
A10	Section           ----------------------->string
100		Total         ----------------------->int

fwrite(name, sizeof(name) , 1, fptr); // write the name once only

fwrite(Class , sizeof(Class ) , 1, fptr); // write the name once only

fwrite(Number, sizeof(Number) , 1, fptr); // write the name once only

fwrite(Section, sizeof(Section) , 1, fptr); // write the name once only

fwrite(Total, sizeof(Total) , 1, fptr); // write the name once only