选择的价值 <select>具有onchange（this.value）的标签

Question

I am trying to get the value of the selection on each change, I tried to log it to the console in my javascript but it doesn't work, this is some of the code from the problem... I am new to programming Please keep the answer simple... Thanks

 function add(x) { var selection = x; console.log(x); } 

 <select class="seletion" onchange="add(this.value)"> <option value="a">A</option> <option value="b">B</option> <option value="c">C</option> <option value="d">D</option> <option value="e">E</option> <option value="f">F</option> <option value="g">G</option> <option value="h">H</option> <option value="i">I</option> <option value="j">J</option> <option value="k">K</option> <option value="l">L</option> <option value="m">M</option> <option value="n">N</option> <option value="o">O</option> <option value="p">P</option> <option value="q">Q</option> <option value="r">R</option> <option value="s">S</option> <option value="t">T</option> <option value="u">U</option> <option value="v">V</option> <option value="w">W</option> <option value="x">X</option> <option value="y">Y</option> </select> 

Answer 1

Try this : Your code looks good to me but somehow function name add is not working, once i change the name of function it starts working, see working snippet

 function showSelection(x) { alert(x); } 

  <select class="seletion" onchange="showSelection(this.value);"> <option value="a">A</option> <option value="b">B</option> <option value="c">C</option> <option value="d">D</option> <option value="e">E</option> <option value="f">F</option> <option value="g">G</option> <option value="h">H</option> <option value="i">I</option> <option value="j">J</option> <option value="k">K</option> <option value="l">L</option> <option value="m">M</option> <option value="n">N</option> <option value="o">O</option> <option value="p">P</option> <option value="q">Q</option> <option value="r">R</option> <option value="s">S</option> <option value="t">T</option> <option value="u">U</option> <option value="v">V</option> <option value="w">W</option> <option value="x">X</option> <option value="y">Y</option> </select> 

Answer 2

ANSWER UPDATE

Reading from HTMLSelectElement you can see a method:

add() Adds an element to the collection of option elements for this select element.

This is the function called and not yours.

Indeed, you can see this in the following example:

 var opt1 = document.createElement("option"); opt1.value = "1"; opt1.text = "Option: Value 1"; function add (x) { var selection = x; console.log(x); } 

 <select class="seletion" onchange="add(opt1);console.log('New option added at the end')"> <option value="a">A</option> <option value="b">B</option> <option value="c">C</option> <option value="d">D</option> <option value="e">E</option> <option value="f">F</option> <option value="g">G</option> <option value="h">H</option> <option value="i">I</option> <option value="j">J</option> <option value="k">K</option> <option value="l">L</option> <option value="m">M</option> <option value="n">N</option> <option value="o">O</option> <option value="p">P</option> <option value="q">Q</option> <option value="r">R</option> <option value="s">S</option> <option value="t">T</option> <option value="u">U</option> <option value="v">V</option> <option value="w">W</option> <option value="x">X</option> <option value="y">Y</option> </select> 

The name of your function add is considered a different function from JS.

Change its name, for example, to add1 or call it as a global function attached to the window object:

 function add1(x) { var selection = x; console.log('add1: ' + x); } function add(x) { var selection = x; console.log('window.add: ' + x); } 

 <select class="seletion" onchange="add1(this.value);"> <option value="a">A</option> <option value="b">B</option> <option value="c">C</option> <option value="d">D</option> <option value="e">E</option> <option value="f">F</option> <option value="g">G</option> <option value="h">H</option> <option value="i">I</option> <option value="j">J</option> <option value="k">K</option> <option value="l">L</option> <option value="m">M</option> <option value="n">N</option> <option value="o">O</option> <option value="p">P</option> <option value="q">Q</option> <option value="r">R</option> <option value="s">S</option> <option value="t">T</option> <option value="u">U</option> <option value="v">V</option> <option value="w">W</option> <option value="x">X</option> <option value="y">Y</option> </select> <select class="seletion" onchange="window.add(this.value);"> <option value="a">A</option> <option value="b">B</option> <option value="c">C</option> <option value="d">D</option> <option value="e">E</option> <option value="f">F</option> <option value="g">G</option> <option value="h">H</option> <option value="i">I</option> <option value="j">J</option> <option value="k">K</option> <option value="l">L</option> <option value="m">M</option> <option value="n">N</option> <option value="o">O</option> <option value="p">P</option> <option value="q">Q</option> <option value="r">R</option> <option value="s">S</option> <option value="t">T</option> <option value="u">U</option> <option value="v">V</option> <option value="w">W</option> <option value="x">X</option> <option value="y">Y</option> </select> 

Answer 3

Here is one more reliable solution

 function addsel() { var selection = document.getElementById("sel1").value; console.log(selection); } 

 <select id="sel1" class="seletion" onchange="addsel()"> <option value="a">A</option> <option value="b">B</option> <option value="c">C</option> <option value="d">D</option> <option value="e">E</option> <option value="f">F</option> <option value="g">G</option> <option value="h">H</option> <option value="i">I</option> <option value="j">J</option> <option value="k">K</option> <option value="l">L</option> <option value="m">M</option> <option value="n">N</option> <option value="o">O</option> <option value="p">P</option> <option value="q">Q</option> <option value="r">R</option> <option value="s">S</option> <option value="t">T</option> <option value="u">U</option> <option value="v">V</option> <option value="w">W</option> <option value="x">X</option> <option value="y">Y</option> </select> 

Answer 4

Using in-line event handlers is not always the best idea. Why not try using the DOM API to handle this scenario?

Remove the 'onchange' handler in the <select> then add the following to your JS script

document.getElementsByClassName('seletion')[0].addEventListener('change', function(){      
  console.log(this.value);
});