Nand to Tetris: string equality test isn't working

Question

This is outputting false instead of true. Why is this?

class Main {
  function void main() {
    var String foo;
    let foo = "bar";

    if (foo = "bar") {
      do Output.printString("true");
    }
    else {
      do Output.printString("false");
    }

    return;
  }
}

I suspect it's because foo and "bar" are each objects, and the = tests whether the starting address of each object is the same (note that in Jack, equality is tested for with a single equals, rather than a double or triple equals). I haven't gotten to chapters 10/11 yet, which is when I'll discover whether or not this hypothesis is true.

Answer 1

Sorry for the late answer, but here it comes. Your program will dynamically create a string on the heap for every occurrence of "bar" and your code will compare two distinct addresses on the heap. The comparison will be false.

How do I know that? I have just finished writing the compiler...