React: How to conditionally style dropdown options?

Im trying to change the className of choosen objects in the mapped array with another array(this.props.notPressAble). This is because i want some of the objects in the array to have another css style

handleOptions = () =>{
    let array = this.props.options.map((option, i) => 
    <a 
    key={i} 
    className={classes.dropdownoptions}>
    {option}</a>)

    for(let x = 0; x < this.props.options.length; x++)
    {
        if(this.props.notPressAble !== undefined)
        {
            for(let y = 0; y < this.props.notPressAble.length; y++)
            {
                if(x == this.props.notPressAble[y])
                {
                    array[x].props.className = classes.dropdownoptionsnotpressable
                }
            }
        }
    }

    return array
}

The code below is where i implement the class for readers too get a better understanding of my problem

 <SideBarContainers name="Planering" notPressAble={[0, 6, 11]}
 options={[
     "Aktiviteter:",
     "+ Ny Aktivitet",
     "Visa Alla Öppna",
     "Visa Försenat",
     "Visa Alla Stängda",
     "Visa Alla Kategoriserat",
     "Att göra:",
     "+ Ny Att göra",
     "Visa Alla Öppna",
     "Visa Alla Stängda",
     "Visa Alla Kategoriserat",
     "Personal planering:",
     "+ Ny post",
     "Visa Alla enkel"

]} />

The problem im having is that array[x].props.className is a readOnly value that cant be changed. Is there another way of doing this?

Why are you using for loops to loop over options and then notPressAble. You could just use includes function and decide which class to apply.

handleOptions = () => {
    let array = this.props.options.map((option, i) => {
      const cls = this.props.notPressAble.includes(i) ? classes.dropdownoptionsnotpressable : classes.dropdownoptions
      return (
        <a key={i} className={cls}>
          {option}
        </a>
      )
    });

    return array;
  };

If you still want to go with your current code then you need to clone the element you want to change and then make the changes like below.

//array[x].props.className = classes.dropdownoptionsnotpressable
array[x] = React.cloneElement(array[x], {className: classes.dropdownoptionsnotpressable});