Hey i am new here and also new to programming i have been given an assignment to make a converter that converts the input number to other number systems such as octal binary etc, so i wrote this long code and its giving me declaration syntax error, i have looked again and again closed all the brackets and everythng please tell me whats wrong here??? and yes i have changed these [] to this () in the last lines because the admin was not allowing me to post it. also hex2oct is not done, i can not figure out a way to convert hexadecimal number to octal number help me i have to submit this tomorow. THanks in advance

#include <conio.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
void dec2hex(long int decimalNumber2)
void dec2bin(long int decimalNumber1, long int quotient1, int binaryNumber1[100], int i1, int j1)
void dec2oct(long int decimalNumber3, long int quotient3, int binaryNumber3[100], int i3, int j3)
void hex2bin(char binaryNumber4[100], int i4, char hexaDecimal4[100])
void hex2dec(int hexadecimalNumber8)
void bin2dec(long int binaryNumber5[25], long int decimalNumber5[25], long int m5=0, long int x5, long int n5, long int z5, long int y5)
void bin2hex(long int binaryNumber6[25], long int decimalNumber6[25], long int m6=0, long int x6, long int n6, long int z6, long int y6)
void bin2oct(long int binaryNumber7[25], long int decimalNumber7[25], long int m7=0, long int x7, long int n7, long int z7, long int y7, long int octalNumber7[25], long int quotient7, long int j7, long int i7=1)
void oct2bin(char octalNumber9[1000], long int i9)
void hex2oct()
void oct2hex(long int octalNumber11[25], long int decimalNumber11[25], long int m11=0, long int x11, long int n11, long int z11, long int y11;)
void oct2dec(long int octalNumber10[25], long int decimalNumber10[25], long int m10=0, long int x10, long int n10, long int z10, long int y10;)
void main(void)
{
int x1;
void dec2bin(void)
{
long int decimalNumber1, quotient1;
int binaryNumber1[100], i1=1, j1;
printf("Enter any decimal number: ");
scanf("%ld", &decimalNumber1);
quotient1=decimalNumber1;
while(quotient1!=0)
{
binaryNumber1[i1++]=quotient1%2;
quotient1=quotient1/2;
}
printf("Equivalent Binary Number is ");
for(j1=i1-1 ;j1> 0;j1--)
{
printf("%d", binaryNumber1[j1]);
}
}


void dec2hex(void)
{
long int decimalNumber2;
printf("Enter any decimal number: ");
scanf("%d", &decimalNumber2);
printf("Equivalent hexadecimal number is: %X", decimalNumber2);
}


void dec2oct(void)
{
long int decimalNumber3, quotient3;
int binaryNumber3[100], i3=1, j3;
printf("Enter any decimal number: ");
scanf("%ld", &decimalNumber3);
quotient3=decimalNumber3;
while(quotient3!=0)
{
binaryNumber3[i3++]= quotient3%8;
quotient3=quotient3/8;
}
printf("Equivalent binary value of Octal number %d: ", decimalNumber3);
for(j3=i3-1; j3>0; j3--)
{
printf("%d", binaryNumber3[j3]);
}
}


void hex2bin(void)
{
char binaryNumber4[100], hexaDecimal4[100];
long int i4=0;
printf("Enter any hexadecimal number: ");
scanf("%s", hexaDecimal4);
printf("\nEquivalent binary value: ");
while(hexaDecimal4[i4])
{
switch(hexaDecimal4[i4])
{
case '0': printf("0000"); break;
case '1': printf("0001"); break;
case '2': printf("0010"); break;
case '3': printf("0011"); break;
case '4': printf("0100"); break;
case '5': printf("0101"); break;
case '6': printf("0110"); break;
case '7': printf("0111"); break;
case '8': printf("1000"); break;
case '9': printf("1001"); break;
case 'A': printf("1010"); break;
case 'B': printf("1011"); break;
case 'C': printf("1100"); break;
case 'D': printf("1101"); break;
case 'E': printf("1110"); break;
case 'F': printf("1111"); break;
case 'a': printf("1010"); break;
case 'b': printf("1011"); break;
case 'c': printf("1100"); break;
case 'd': printf("1101"); break;
case 'e': printf("1110"); break;
case 'f': printf("1111"); break;
default: printf("\nInvalid hexadecimal digit %c ", hexaDecimal4[i4]);
}
i4++;
}
}


void hex2dec(void)
{
int hexadecimalNumber8;
printf("Enter any hexadecimal number: ");
scanf("%X", &hexadecimalNumber8);
printf("Equivalent decimal number is: %d", hexadecimalNumber8);
getch();
}


void bin2dec(void)
{
long int binaryNumber5[25], decimalNumber5[25], m5=0, x5, n5, z5, y5;
printf("Enter the number of bits you are going to enter: ");
scanf("%ld", &n5);
printf("Enter a binary number and press enter after entering every bit: ");
for (m5; m5<n5; m5++)
{
scanf("%ld", &binaryNumber5[m]);
}
if (n5==1)
{
n5=n5-1;
x5=pow(2, n5);
decimalNumber5[0]=binaryNumber5[0]*x5;
y5=decimalNumber5[0];
}
if (n5==2)
{
n5=n5-1;
x5=pow(2, n5);
decimalNumber5[0]=binaryNumber5[0]*x5;
n5=n5-1;
x5=pow(2, n5);
decimalNumber5[1]=binaryNumber5[1]*x5;
y5=decimalNumber5[0]+decimalNumber5[1];
}
if (n5>=3)
{
z5=n5-1;
for (m5=0; m5<n5; m5++)
{
x5=pow(2, z5);
z5=z5-1;
decimalNumber5[m]=binaryNumber5[m]*x5;
}
y5=decimalNumber5[0]+decimalNumber5[1];
for (m5=2; m5<n; m5++)
{
y5=y5+decimalNumber5[m5];
}
}
printf("Equivalent decimal value: %ld", y5);
getch();
}


void bin2hex(void)
{

long int binaryNumber6[25], decimalNumber6[25], m6=0, x6, n6, z6, y6;
printf("Enter the number of bits you are going to enter: ");
scanf("%ld", &n6);
printf("Enter a binary number and press enter after entering every bit: ");
for (m6; m6<n6; m6++)
{
scanf("%ld", &binaryNumber6[m6]);
}
if (n6==1)
{
n6=n6-1;
x6=pow(2, n6);
decimalNumber6[0]=binaryNumber6[0]*x6;
y6=decimalNumber6[0];
}
if (n6==2)
{
n6=n6-1;
x6=pow(2, n6);
decimalNumber6[0]=binaryNumber6[0]*x6;
n6=n6-1;
x6=pow(2, n6);
decimalNumber6[1]=binaryNumber6[1]*x6;
y6=decimalNumber6[0]+decimalNumber6[1];
}
if (n6>=3)
{
z6=n6-1;
for (m6=0; m6<n6; m6++)
{
x6=pow(2, z6);
z6=z6-1;
decimalNumber6[m6]=binaryNumber6[m6]*x6;
}
y6=decimalNumber6[0]+decimalNumber6[1];
for (m6=2; m6<n6; m6++)
{
y6=y6+decimalNumber6[m6];
}
}
printf("Equivalent hexadecimal value: %X", y6);
getch();
}


void bin2oct(void)
{

long int binaryNumber7[25], decimalNumber7[25], m7=0, x7, n7, z7, y7, octalNumber7[25], quotient7, j7, i7=1;
printf("Enter the number of bits you are going to enter: ");
scanf("%ld", &n7);
printf("Enter a binary number and press enter after entering every bit: ");
for (m7; m7<n7; m7++)
{
scanf("%ld", &binaryNumber7[m7]);
}
if (n7==1)
{
n7=n7-1;
x7=pow(2, n7);
decimalNumber7[0]=binaryNumber7[0]*x7;
y7=decimalNumber7[0];
}
if (n7==2)
{
n7=n7-1;
x7=pow(2, n7);
decimalNumber7[0]=binaryNumber7[0]*x7;
n7=n7-1;
x7=pow(2, n7);
decimalNumber7[1]=binaryNumber7[1]*x7;
y7=decimalNumber7[0]+decimalNumber7[1];
}
if (n7>=3)
{
z7=n7-1;
for (m7=0; m7<n7; m7++)
{
x7=pow(2, z7);
z7=z7-1;
decimalNumber7[m]=binaryNumber7[m]*x7;
}
y7=decimalNumber7[0]+decimalNumber7[1];
for (m7=2; m7<n7; m7++)
{
y7=y7+decimalNumber7[m7];
}
}
quotient7=y7;
while(quotient7!=0)
{
octalNumber7[i++]= quotient7%8;
quotient7=quotient7/8;
}
printf("Equivalent Octal value: ");
for(j7=i7-1; j7>0; j7--)
{
printf("%d", octalNumber7[j7]);
}
getch();
}



void oct2bin(void)
{
char octalNumber9[1000];
long int i9=0;
printf("Enter any octal number: ");
scanf("%s", octalNumber9);
printf("Equivalent binary value: ");
while(octalNumber9[i])
{
switch(octalNumber9[i])
{
case'0':printf("000"); break;
case'1':printf("001"); break;
case'2':printf("010"); break;
case'3':printf("011"); break;
case'4':printf("100"); break;
case'5':printf("101"); break;
case'6':printf("110"); break;
case'7':printf("111"); break;
default:printf("\nInvalid octal digit %c ", octalNumber9[i9]);
}
i9++;
}
getch();
}



void oct2dec(void)
{
long int octalNumber10[25], decimalNumber10[25], m10=0, x10, n10, z10, y10;
printf("Enter the number of bits you are going to enter: ");
scanf("%ld", &n10);
printf("Enter a binary number and press enter after entering every bit: ");
for (m10; m10<n10; m10++)
{
scanf("%ld", &octalNumber10[m10]);
}
if (n10==1)
{
n10=n10-1;
x10=pow(8, n10);
decimalNumber10[0]=octalNumber10[0]*x10;
y10=decimalNumber10[0];
}
if (n10==2)
{
n10=n10-1;
x10=pow(8, n10);
decimalNumber10[0]=octalNumber10[0]*x10;
n10=n10-1;
x10=pow(8, n10) ;
decimalNumber10(1)=octalNumber10[1]*x10;
y10=decimalNumber10[0]+decimalNumber10[1];
}
if (n10>=3)
{
z10=n10-1;
for (m10=0; m10<n10; m10++)
{
x10=pow(8, z10);
z10=z10-1;
decimalNumber10[m10]=octalNumber10[m10]*x10;
}
y10=decimalNumber10[0]+decimalNumber10[1];
for (m10=2; m10<n10; m10++)
{
y10=y10+decimalNumber10[m10];
}
}
printf("Equivalent decimal value: %ld", y10);
getch();
}



void oct2hex(void)
{
long int octalNumber11[25], decimalNumber11[25], m11=0, x11, n11, z11, y11;
printf("Enter the number of bits you are going to enter: ");
scanf("%ld", &n11);
printf("Enter a binary number and press enter after entering every bit: ");
for (m11; m11<n11; m11++)
{
scanf("%ld", &octalNumber11[m11]);
}
if (n11==1)
{
n11=n11-1;
x11=pow(8, n11);
decimalNumber11[0]=octalNumber11[0]*x11;
y11=decimalNumber11[0];
}
if (n11==2)
{
n11=n11-1;
x11=pow(8, n11);
decimalNumber11[0]=octalNumber11[0]*x11;
n11=n11-1;
x11=pow(8, n11);
decimalNumber11[1]=octalNumber11[1]*x11;
y11=decimalNumber11[0]+decimalNumber11[1];
}
if (n11>=3)
{
z11=n11-1;
for (m11=0; m11<n11; m11++)
{
x11=pow(8, z11);
z11=z11-1;
decimalNumber11[m11]=octalNumber11[m11]*x11;
}
y11=decimalNumber11(0)+decimalNumber11(1);
for (m11=2; m11<n11; m11++)
{
y11=y11+decimalNumber11(m11);
}
}
printf("Equivalent Hexadecimal value: %X", y11);
getch();
}



printf ("Select the number, what do you want to do:\n1.Decimal to Binary\n2.Decimal to Octal\n3.Decimal to Hexa-Decimal\n4.Binary to Decimal\n5.Binary to Octal\n6.Binary to Hexa-Decimal\n7.Octal to Decimal\n8.Octal to Binary\n9.Octal to Hexa-Decimal\n10.Hexa-Decimal to Decimal\n11.Hexa-Decimal to Octal\n12.Hexa-Decimal to Binary");
scanf ("%d", &x1);
switch(x1)
{
case '1': dec2bin(); break;
case '2': dec2oct(); break;
case '3': dec2hex(); break;
case '4': bin2dec(); break;
case '5': bin2oct(); break;
case '6': bin2hex(); break;
case '7': oct2dec(); break;
case '8': oct2bin(); break;
case '9': oct2hex(); break;
case '10': hex2dec(); break;
case '11': hex2oct(); break;
case '12': hex2bin(); break;
}
}