java - Getting Key of Generic List -


यह प्रश्न एक सटीक डुप्लिकेट है: < / P>

  • का कहना है कि मेरे पास एक प्रकार की सूची है, जैसे a.getKey () (यह एक मौजूद नहीं है ..)

    मैं सूची प्रकार संग्रह की कुंजी प्राप्त करने की कोशिश कर रहा हूँ।

    क्या इसमें कोई भी विधि निर्मित है?

    यहां Java.util.List एपीआई है, जो मुफ्त ऑनलाइन प्रदान की जाती है । जब आप अंतर्निहित तरीकों के बारे में प्रश्न पूछते हैं, तो आपको एपीआई पढ़ना चाहिए।

    मैं इसे लेता हूं आप & lt; E & gt; के बाद कर सकते हैं, जिस वर्ग का ऑब्जेक्ट में संग्रहीत है आपकी सूची

    आप सही हैं, क्योंकि इस जानकारी को पाने के लिए कोई मूल पद्धति नहीं है, इसलिए आपको अपना खुद का तरीका बनाना है। मेरी सोच की पंक्ति:

    1. जांचें कि सूची खाली नहीं है
    2. पहले तत्व प्राप्त करें और इसे वस्तु
    3. ऑब्जेक्ट क्लास में अपने ऑब्जेक्ट क्लास को वापस करने के लिए getClass () विधि का उपयोग करें

      आप बाकी को समझते हैं कुछ भी असंभव नहीं है, आपको कभी-कभार रचनात्मक होना पड़ता है।

      - ऑब्जेक्ट एपीआई

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