You have to search in the array like:
function changeDesc( value, desc ) {
for (var i in projects) {
if (projects[i].value == value) {
projects[i].desc = desc;
break; //Stop this loop, we found it!
}
}
}
and use it like
var projects = [ ... ];
changeDesc ( 'jquery-ui', 'new description' );
UPDATE:
To get it faster:
var projects = {
jqueryUi : {
value: 'lol1',
desc: 'lol2'
}
};
projects.jqueryUi.desc = 'new string';
(In according to Frédéric’s comment you shouldn’t use hyphen in the object key, or you should use “jquery-ui” and projects[“jquery-ui”] notation.)