I have 2 variable with values and character '&' to determinate parameter (like URL parameter).

Note: This is not a parameter from URL and not is a Array, just a string storage on variable!

1. variable1 = "value1=bla&value2=ble&value3=bli&value4=blo&value5=blu"
2. variable2 = "value2=car&value4=yellow&value9=big"

I need compare 2 variables and if have same parameter on variable1 and variable2, i need exclude parameter from variable1 and use parameter of variable2.

Like this:

1. value1=bla&value2=car&value3=bli&value4=red&value5=blu&value9=big