filelist-part-6.js

//store required extensions
const requiredExts = [".png", ".jpg", ".jpeg"];
//store error
const valError = [];
//loop through object
for (let file of fileInpFiles){
    //retrieve extension from name
    const ext = file.name.substring(file.name.lastIndexOf('.'));
    //check if it matches with the required extension
    if ( !requiredExts.includes( ext ) ){
        //store file name that doesn't match the extension
        valError.push( file.name );
    }
}
//check if there's a validation error
if( valError.length !== 0 ){
    valError.forEach( f => {
        console.log(`${f} is not supported`);
    } );
}