JavaScript È°¿ëÆÁ
2018.11.24 / 11:32

[JavaScript] Select ű×ÀÇ °ªÀ» ¼ø¼­, Index·Î ã±â, selectedIndex

hanulbit
Ãßõ ¼ö 175

select ű׿¡¼­ ¼±ÅÃµÈ °ªÀÌ ÀÖ´Â °æ¿ì ¸î¹ø° ÇØ´çÇÏ´ÂÁö °ªÀ» ¾Ë·Á¸é ¾î¶»°Ô ¾Ë ¼ö ÀÖÀ»±î¿ä? ¾Æ·¡ ¹æ¹ýÀº ¼±ÅÃµÈ °ªÀ» ¾ò´Â ÀÚ¹Ù½ºÅ©¸³Æ® ¹æ¹ýÀÔ´Ï´Ù.


# selectedIndex¸¦ »ç¿ëÇÑ select ű×ÀÇ ¼±Å𪠾˾Ƴ»±â
select ű׿¡¼­ ¼±ÅÃµÈ °ªÀÇ À§Ä¡ ¶Ç´Â ¼ø¼­ index¸¦ ¾Ë·Á¸é selectedIndex ¼Ó¼ºÀ» »ç¿ëÇÕ´Ï´Ù. ÀÌ ¼Ó¼ºÀº ¼±ÅÃµÈ Å±×ÀÇ index ³Ñ¹ö¸¦ ¹ÝȯÇØÁÝ´Ï´Ù. °£´ÜÇÑ »ç¿ë ¹æ¹ýÀº ¾Æ·¡¿Í °°ÀÌ »ç¿ëÇÕ´Ï´Ù!

selectElement.selectedIndex;

Âü°í·Î ¼±ÅÃµÈ <option> ű׿¡ Àû¿ëµÈ °ªÀ» ¾Ë·Á¸é element.value ÇÁ·ÎÆÛƼ¸¦ »ç¿ëÇÏ¿© ±× °ªÀ» ¾Ë ¼ö ÀÖÁÒ. ÇÏÁö¸¸ index °ªÀÎ ¼ø¼­¸¦ ¾Ë¾Æ¾ßÇÑ´Ù¸é selectedIndex¸¦ »ç¿ëÇÕ´Ï´Ù. °£´ÜÇÏ°Ô ¼±ÅÃµÈ °ªÀÇ ÇØ´çÀ§Ä¡¸¦(¼ø¼­°ª) ºÒ·¯¿É´Ï´Ù. ±×·³ ¾Æ·¡ ¿¹Á¦¸¦ Âü°íÇϼ¼¿ä.



# select ű×ÀÇ selectedIndex ¿¹Á¦º¸±â

¾Æ·¡ select űװ¡ °ªÀ» °¡Áö´Â °æ¿ì ÀÌ °ªÀÇ index, À§Ä¡¸¦ ¾ò´Â ¿¹Á¦ÀÔ´Ï´Ù.
@ selectedIndex.html
<select class="selectTest">
    <option name="test1" selected="selected">Test1</option>
    <option name="test2">Test2</option>
    <option name="test3">Test3</option>
</select>

ÀÌÁ¦ ¾Æ·¡¿Í °°ÀÌ ½ºÅ©¸³Æ®¸¦ »ç¿ëÇÏ¿© È®ÀÎÇغ¾½Ã´Ù.
var test = document.getElementsByClassName("selectTest");
// test º¯¼ö¿¡ selectTest¶õ Ŭ·¡½º¸íÀ» °¡Áø ¿ä¼Ò¸¦ ÀúÀå

var indexNo = test[0].selectedIndex;
// test º¯¼öÀÇ ¼±ÅÃµÈ °ªÀ» indexNo¿¡ ÀúÀå

console.log(indexNo);

À§ ½ºÅ©¸³Æ®¸¦ ½ÇÇàÇϸé indexNoÀÇ ¹Ýȯ°ªÀ¸·Î ¾Æ·¡¿Í °°ÀÌ Äֿܼ¡ Ãâ·ÂµË´Ï´Ù.
0 // Á¦ÀÏ ¾Õ¿¡ ÀÖÀ¸¹Ç·Î 0À» ¹ÝȯÇÔ

Âü°í·Î, ½ºÅ©¸³Æ®¸¦ ½ÇÇà½ÃÅ°¸é ¸Ç À§ºÎÅÍ (0, 1, 2, ...) ¼ø¼­·Î °ªÀ» °¡Á®¿É´Ï´Ù. ½ÃÀÛ°ªÀÌ 0ºÎÅÍ Áõ°¡ÇϰԵ˴ϴÙ.



! ¿¹Á¦ µ¿ÀÛÇغ¸±â±æÁ¦·Î ¾Æ·¡ÀÇ select ű׿¡¼­ °ªÀ» ¼±ÅÃÇغ¸¼¼¿ä! ÇØ´ç index°ªÀ» Ãâ·ÂÇϰԵ˴ϴÙ.
#inde