Question

Why does this just not work out for me ?

<script type="text/javascript">
var gene="ATTAHATHHATTCGTA";
var i=0;
for (;i<gene.lenth;i++)
{
   if(gene[i]=='H')
     gene[i]='G';
}
</script>

I change it by use of replace as follows

<script type="text/javascript">
var gene="ATTAHATHHATTCGTA";
var i=0;
for (;i<gene.lenth;)
{
   var pos=gene.replace("H","G");
   i+=pos;
}
</script>

but I am still out of luck. Thank you for any help.

Answer 1

The String.replace method is used much more simply:

var gene="ATTAHATHHATTCGTA"; 
gene = gene.replace("H", "G", "g"); // The last "g" means "replace all occurrences"

Simple as that.

However, this is not going to work on all browsers. To make it portable, you have to specify the first parameter as a regular expression, like this:

var gene="ATTAHATHHATTCGTA"; 
gene = gene.replace(/H/g, "G"); // The /g means "replace all occurrences"