Geek asks and answers

Can I simplify a few if-else statements?

Do I have the following code in javascript?

if ($(form).data('action') == "Edit") {
  xx
} else if ($(form).data('action') == "Create"){
  xy
} else if ($(form).data('action') == "Delete"){
  xz
}

Is it possible for me to simplify this and also have some default path?

+3
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8 answers

You can also create an object that contains your actions:

var Actions = {
    'Edit' : function () {},
    'Create' : function () {},
    'Delete' : function () {}
};

var action = $(form).data('action');

if (Actions.hasOwnProperty(action)) {
    Actions[action]();
}
+11
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It looks like you are describing the / case switch, but I don't think the switch case is better than a few if / else structures. I prefer to use hashes of objects:

var actionObj = {
  "Edit": xx,
  "Create": xy,
  "Delete": xz
};

if (actionObj[act]) {
  // do whatever with actionObj[act] you need to
} else {
  // do your default action
}

This works especially well when values ​​are actually functions, then you can just call them:

var actionObj = {
  "Edit": function () {},
  "Create": function () {},
  "Delete": function () {}
};

if (actionObj[act]) {
  actionObj[act]();
} else {
  // default action
}
+5
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, , else

switch(n)
{
case 1:
  execute code block 1
  break;
case 2:
  execute code block 2
  break;
default:
  code to be executed if n is different from case 1 and 2
}
+4

$(form).data('action'); :

var action = $(form).data('action');

if (action === 'Edit') {
    //
} else if (action === 'Create') {
    //
} else if (action === 'Delete') {
    //
}
+2

switch .

(hashmap):

var actions = {
    Edit: function () {
        // xx
    },
    Create: function () {
        // xy
    },
    Delete: function () {
        // xz
    }
};

var action = actions[$(form).data("action")];

if (action) {
    action();
} else {
    // unknown/default action
}
+2

use switch housing:

var action = $(form).data('action')
switch(action)
{
case 'Edit': xx;
break;
case 'Create': yy;
break;
case 'Delete': zz;
break;
default: caption ="default";
}

or you can use the ternary operator (true? 1: 0)

+1
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var Actions = {
    'Edit' : function () {},
    'Create' : function () {},
    'Delete' : function () {},
    'default': function () {}
},

action = $(form).data('action');
Actions[action]() || Actions[default]();
0
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Try CASE from here: http://www.tutorialspoint.com/javascript/javascript_switch_case.htm

An example of them:

<script type="text/javascript">
<!--
var grade='A';
document.write("Entering switch block<br />");
switch (grade)
{
   case 'A': document.write("Good job<br />");
            break;
   case 'B': document.write("Pretty good<br />");
            break;
   case 'C': document.write("Passed<br />");
            break;
   case 'D': document.write("Not so good<br />");
            break;
   case 'F': document.write("Failed<br />");
            break;
  default:  document.write("Unknown grade<br />")
}
document.write("Exiting switch block");
//-->
</script>
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