将["a"=1,"b"=2] 转为对象

var obj = {};
var arr = ["a=1","b=2","c=3"];

for (var x in arr){
    var split = arr[x].split('=');
    obj[split[0] ] = split[1];
}

eval实现
  var arr = ["a=1","b=2","c=3"];
    o = arrToObject(arr);
    alert(o);
    alert(o.a + " " + o.b + " " + o.c);

    function arrToObject(arr){
         var strJs = '({';
        for(var i=0;i<arr.length;i+=1){
            var as = arr[i].split("=");
            strJs = strJs + as[0] + ':' +'"' + as[1] + '"' +',';
        }
        strJs = strJs.substr(0,strJs.length-1) + '})';
        return eval(strJs);
        }

var obj = JSON.parse('{' + arr.join(',').replace(/(\w)=/g, '"$1":') + '}');