如何通过调用javascript中的函数来获取两个按钮的不同值

Question

 function getValue(){ var v = document.getElementById("btn2").value; document.getElementById("display").value += v; } 

  <input type ="text" id = "display" value = "" ></input> <tr> <td> <input type = "button" id = "btn2" value="7" onclick="getValue(this)" ></input> </td> <td> <input type = "button" id = "btn2" value="8" onclick="getValue(this)" ></input> </td> </tr> 

I just want to different value by clicking 8 or 7 button. but every time i got 7 as result what can i do please help.. and more i want to pass "this" in getValue(this) so that by clicking that button get the all information that buttton. plz help me thanks

Answer 1

Your IDs, in dom should be unique. jQuery is returning only the first element when calling $('#idstring'); as document.getElementById('#idstring') also does.

In this case, you could use className.

You also pass a parameter to the function, but you don't use it.

I edited this snippet to show how to bind this to the function before calling it. Like this, you can use 'this' if it's your thing.

 function getValue(el) { document.getElementById("display").value = el.value; } function getValue2() { document.getElementById("display").value = this.value; } 

 <input type="text" id="display" value=""></input> <tr> <td> <input type="button" class="btn2" value="7" onclick="getValue(this)"></input> </td> <td> <input type="button" class="btn2" value="8" onclick="getValue2.bind(this)()"></input> </td> </tr> 

Answer 2

1. Make sure your ids are unique.

2. Make use of the argument ( this ) that you are passing.

 function getValue(button){ var v = document.getElementById(button.id).value; document.getElementById("display").value += v; } 

  <input type ="text" id = "display" value = "" ></input> <tr> <td> <input type = "button" id = "btn1" value="7" onclick="getValue(this)" ></input> </td> <td> <input type = "button" id = "btn2" value="8" onclick="getValue(this)" ></input> </td> </tr> 

Answer 3

I see you already have answers to your question. However a cleared way might be to use classes.

$(".my_buttons").click(function(){
    $("#display").val($(this).val());
});

<input type="text" id="display" />
<input type="button" class="my_buttons" value="7" />
<input type="button" class="my_buttons" value="8" />