Rna

class RnaTranscription {

String transcribe(String dnaStrand) {
    StringBuilder allstring = new StringBuilder();
    for (char dna: dnaStrand.toCharArray()){
    switch(dna){
        case 'G': 
            allstring.append('C');
            break;
        case 'C':
            allstring.append('G'); 
            break;
        case 'T':
            allstring.append('A');
            break;
        case 'A':
            allstring.append('U'); 
            break;
        default:
            allstring.append(' ');  
    }   
}
     return allstring.toString();

}
}