ããsubstring æ¹æ³ç¨äºæåå符串ä¸ä»äºä¸¤ä¸ªæå®ä¸æ ä¹é´çå符
ããsubstring(start,end)
ããå¼å§åç»æçä½ç½®ï¼ä»é¶å¼å§çç´¢å¼
ããåæ° æè¿°
ããstart å¿
éãä¸ä¸ªéè´çæ´æ°ï¼è§å®è¦æåçå串ç第ä¸ä¸ªåç¬¦å¨ stringObject ä¸çä½ç½®ã
ããstop å¯éãä¸ä¸ªéè´çæ´æ°ï¼æ¯è¦æåçå串çæåä¸ä¸ªåç¬¦å¨ stringObject ä¸çä½ç½®å¤ 1ãå¦æçç¥è¯¥åæ°ï¼é£ä¹è¿åçå串ä¼ä¸ç´å°å符串çç»å°¾ã
ããè¿åå¼
ããä¸ä¸ªæ°çå符串ï¼è¯¥å符串å¼å
å« stringObject çä¸ä¸ªåå符串ï¼å
¶å
容æ¯ä» start å¤å° stop-1 å¤çææå符ï¼å
¶é¿åº¦ä¸º stop å startã
ãã说æ
ããsubstring æ¹æ³è¿åçå串å
æ¬ start å¤çå符ï¼ä½ä¸å
æ¬ end å¤çå符ã
ããå¦æ start ä¸ end ç¸çï¼é£ä¹è¯¥æ¹æ³è¿åçå°±æ¯ä¸ä¸ªç©ºä¸²ï¼å³é¿åº¦ä¸º 0 çå符串ï¼ã
ããå¦æ start æ¯ end 大ï¼é£ä¹è¯¥æ¹æ³å¨æåå串ä¹åä¼å
交æ¢è¿ä¸¤ä¸ªåæ°ã
ããå¦æ start æ end 为è´æ°ï¼é£ä¹å®å°è¢«æ¿æ¢ä¸º 0ã
ãã2.substr æ¹æ³
ããå®ä¹åç¨æ³
ããsubstr æ¹æ³ç¨äºè¿åä¸ä¸ªä»æå®ä½ç½®å¼å§çæå®é¿åº¦çåå符串ã
ããè¯æ³
ããstringObject.substr(start [, length ])
ããåæ° æè¿°
ããstart å¿
éãæéçåå符串çèµ·å§ä½ç½®ãå符串ä¸ç第ä¸ä¸ªå符çç´¢å¼ä¸º 0ã
ããlength å¯éãå¨è¿åçåå符串ä¸åºå
æ¬çå符个æ°ã
ãã说æ
ããå¦æstart为è´æ°ï¼åstart=str.length+startã
ããå¦æ length 为 0 æè´æ°ï¼å°è¿åä¸ä¸ªç©ºå符串ã
ããå¦æ没ææå®è¯¥åæ°ï¼ååå符串å°å»¶ç»å°stringObjectçæåã
ãã举ä¾ï¼
ããvar str = "0123456789";
ããalert(str.substring(0));------------"0123456789"
ããalert(str.substring(5));------------"56789"
ããalert(str.substring(10));-----------""
ããalert(str.substring(12));-----------""
ããalert(str.substring(-5));-----------"0123456789"
ããalert(str.substring(-10));----------"0123456789"
ããalert(str.substring(-12));----------"0123456789"
ããalert(str.substring(0,5));----------"01234"
ããalert(str.substring(0,10));---------"0123456789"
ããalert(str.substring(0,12));---------"0123456789"
ããalert(str.substring(2,0));----------"01"
ããalert(str.substring(2,2));----------""
ããalert(str.substring(2,5));----------"234"
ããalert(str.substring(2,12));---------"23456789"
ããalert(str.substring(2,-2));---------"01"
ããalert(str.substring(-1,5));---------"01234"
ããalert(str.substring(-1,-5));--------""
ããalert(str.substr(0));---------------"0123456789"
ããalert(str.substr(5));---------------"56789"
ããalert(str.substr(10));--------------""
ããalert(str.substr(12));--------------""
ããalert(str.substr(-5));--------------"56789"
ããalert(str.substr(-10));-------------"0123456789"
ããalert(str.substr(-12));-------------"0123456789"
ããalert(str.substr(0,5));-------------"01234"
ããalert(str.substr(0,10));------------"0123456789"
ããalert(str.substr(0,12));------------"0123456789"
ããalert(str.substr(2,0));-------------""
ããalert(str.substr(2,2));-------------"23"
ããalert(str.substr(2,5));-------------"23456"
ããalert(str.substr(2,12));------------"23456789"
ããalert(str.substr(2,-2));------------""
ããalert(str.substr(-1,5));------------"9"
ããalert(str.substr(-1,-5));-----------""
温馨提示:答案为网友推荐,仅供参考