I am using react. I have a function that concatenates the keys of an object and returns the result as a string. I am getting a error that looks like this:
Line 64:7: Expected an assignment or function call and instead saw an expression no-unused-expressions

The function that I have is shown below.

```
const allConcat = (listOfObj) => {
    let stringConcat = '';
    Object.keys(listOfObj).map((item, i)=>{
      (listOfObj[item] === 1)? stringConcat += item : null
    });
    return stringConcat
  }

```

Here is a for each version and i am also getting an error for this.

```
  const allConcat = (listOfObj) => {
    let stringConcat = '';
    Object.keys(listOfObj).forEach(item =>{
      (listOfObj[item] === 1)? stringConcat += item : null
    });
    return stringConcat
  }

```

Please let me know what I can do to get rid of this error. Besides disabling the linter.