Full Stack Implementation in C programming language

#include<stdio.h>
#include <stdbool.h>
#define max_size 100
int arr[max_size], top = -1;
bool isFull()
{
    if(top == (max_size - 1)){
        printf("Stack is Full!!\n");
        return true;
    }else{
        printf("Stack is Not Full!!!. You can insert Value!!\n");
        return false;
    }
}
bool isempty(){
    if(top == -1){
        return true;
    }else{
        return false;
    }
}
void push()
{
    if(isFull()){
        printf("Stack is Full!!\n");
    }else{
        int value;
        printf("Enter the value: ");
        scanf("%d", &value);
        top++;
        arr[top] = value;
        printf("%d is inserted into stack.\n", value);
    }
}
void pop()
{
    if(isempty()){
        printf("\nStack is Empty!!\n");
    }
    else{
        int value = arr[top];
        printf("%d is popped.\n", value);
        top = top - 1;
    }
}
void stack_size()
{
    printf("Size of the array is: %d.\n", top + 1);
}
void print_arr()
{
    printf("Array Elements are: ");
    for(int i = 0; i < (top + 1); i++){
        printf("%d ", arr[i]);
    }
    printf("\n\n");
}
int main()
{
    int n;
    while(1){
        printf("Press 1 for push 2 for pop 3 for array elements 4 for size: ");
        scanf("%d", &n);
        switch(n){
        case 1:
            push();
            break;
        case 2:
            pop();
            break;
        case 3:
            print_arr();
            break;
        case 4:
            stack_size();
            break;
        }
    }
    return 0;
}