1.方法一:
獲取官方定義的屬性直接使用:
元素節點.屬性名
得到元素對應屬性的屬性值
舉例:獲取placeholder的屬性值
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>js_excise</title> <script src="./js/js_excise.js" type="text/javascript" charset="utf-8"></script> </head> <body style="height: 187.5rem;"> <input id="in" type="text" name="Text" placeholder="please your name"> <script type="text/javascript"> var js = document.getElementById('in') console.log(js.placeholder) </script> </body> </html>
輸出:
修改對應屬性的屬性值:
元素節點.屬性名=新的屬性值
舉例:將placeholder="please your name"改為‘please enter your name’
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>js_excise</title> <script src="./js/js_excise.js" type="text/javascript" charset="utf-8"></script> </head> <body style="height: 187.5rem;"> <button onclick="func()">更新</button> <input id="in" type="text" name="Text" placeholder="please your name"> <script type="text/javascript"> var js = document.getElementById('in') console.log(js.placeholder) function func(){ js.placeholder = 'please enter your name' console.log(js.placeholder) } </script> </body> </html>
輸出:
2.方法二:
元素節點.getAttribute("屬性名")
得到元素對應屬性的屬性值
注意:該方法還可以獲取自定義屬性
舉例1:獲取placeholder屬性的值
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>js_excise</title> <script src="./js/js_excise.js" type="text/javascript" charset="utf-8"></script> </head> <body style="height: 187.5rem;"> <button onclick="func()">更新</button> <input id="in" type="text" name="Text" placeholder="please your name"> <script type="text/javascript"> var js = document.getElementById('in') console.log(js.getAttribute('placeholder')) </script> </body> </html>
輸出:
舉例2:獲取自定義屬性my的值
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>js_excise</title> <script src="./js/js_excise.js" type="text/javascript" charset="utf-8"></script> </head> <body style="height: 187.5rem;"> <button onclick="func()">更新</button> <input id="in" type="text" name="Text" placeholder="please your name" my='abner'> <script type="text/javascript"> var js = document.getElementById('in') console.log(js.getAttribute('my')) </script> </body> </html>
輸出:
修改元素對應屬性的屬性值
元素節點.setAttribute("屬性名",“新的屬性值”)
舉例:
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>js_excise</title> <script src="./js/js_excise.js" type="text/javascript" charset="utf-8"></script> </head> <body style="height: 187.5rem;"> <button onclick="func()">更新</button> <input id="in" type="text" name="Text" placeholder="please your name" my='abner'> <script type="text/javascript"> var js = document.getElementById('in') console.log('my更改前:'+js.getAttribute('my')) function func(){ js.setAttribute('my','hello world') console.log('my更改后:'+js.getAttribute('my')) } </script> </body> </html>
輸出: