page 194, eval() problem

keenlearner · December 16th, 2006, 03:10 AM

I am wodering why my code does not work when using eval, but it works without using eval() method. Can i know where am i suppose to use the eval() method and when ?

This is my code that does NOT alert :

Code:

<script type="text/javascript">
var b = {
    "c" : ["red", "white", "blue"],
    "d" : [2,4]
}

var e = eval("("+ b +")");
alert(e.c[0]);
</script>

This is my code that alert :

Code:

<script type="text/javascript">
var b = {
    "c" : ["red", "white", "blue"],
    "d" : [2,4]
}

alert(b.c[0]);
</script>

joefawcett · December 16th, 2006, 06:14 AM

You only need eval when you are trying to turn a string, normally received from a web service, into interpreted JavaScript. In the example above you already have code. Try:

Code:

var s = "{c: ["red\", \"white\", \"blue\"], d: [2, 4]}";
var e = eval("(" + s + ")");
alert(e.c[0]);

--

Joe (Microsoft MVP - XML)

keenlearner · December 16th, 2006, 08:27 AM

Thank's joe, your code works and also my code after i notice that you remove the double quote strings on key name and escape the double quotes on the values. Now i get it. Thank's again