Question

To access the array indice at the xth position we can use some sort of illustration as shown below

#include<iostream>
using namespace std;
int main(){
    float i[20];
    for(int j=0;j<=20;j++)
        i[j]=0;
}

However the following piece of code does not work

#include<iostream>

using namespace std;

float oldrand[55];
int jrand;

void advance_random(){
    int j1;
        float new_random;

    for(j1=0;j1<=23;j1++){
        int temp = j1+30;
        new_random = (oldrand[j1]) - (oldrand[temp]);
        if(new_random <0.0)
            new_random = new_random+1;
        oldrand[j1] = new_random;
    }
    for(j1=24;j1<=54;j1++){
        new_random[j1] = oldrand[j1] - oldrand[j1-23];
        if(new_random[j1]<0.0)
            new_random[j1] = new_random + 1;
        oldrand[j1]=new_random;
    }
}

I recieve the following error

ga.cpp:20: error: invalid types ‘float[int]’ for array subscript
ga.cpp:21: error: invalid types ‘float[int]’ for array subscript
ga.cpp:22: error: invalid types ‘float[int]’ for array subscript

I am not able to find a mistake in my code please help me

Answer 1

new_random isn’t declared as an array of floats, it’s declared as a float. The compiler is trying to tell you you can’t index into a float.