diff --git a/TODO.md b/TODO.md
index 8afd260..e695e00 100644
--- a/TODO.md
+++ b/TODO.md
@@ -31,14 +31,14 @@ After some additional development:
   - [x] Print stack
 - [x] Assembler
 - [ ] VM execution
-  - [ ] Stack operations (nil, integer, float, string, function)
+  - [x] Stack operations (nil, integer, float, string, function)
     - [x] Integer
     - [x] Float
     - [x] String
-  - [ ] Expressions
+  - [x] Expressions
     - [x] Integer
     - [x] Float
-    - [ ] String
+    - [x] String
   - [ ] Local/global variables
   - [ ] Functions
   - [ ] Constants
diff --git a/src/vm/expr.cc b/src/vm/expr.cc
index 11c7796..67123ea 100644
--- a/src/vm/expr.cc
+++ b/src/vm/expr.cc
@@ -10,12 +10,24 @@ namespace tyche::vm {
 std::function<Value(Value const&, Value const&)> binary_ops[(size_t) BinaryOperationType::COUNT][(size_t) Type::COUNT][(size_t) Type::COUNT];
 
 static int init_ = []() {
-    for (size_t i = 0; i < (size_t) BinaryOperationType::COUNT; ++i)
-        for (size_t j = 0; j < (size_t) Type::COUNT; ++j)
-            for (size_t k = 0; k < (size_t) Type::COUNT; ++k)
+    // every combination, except when explicit, return type error
+    for (size_t i = 0; i < (size_t) BinaryOperationType::COUNT; ++i) {
+        for (size_t j = 0; j < (size_t) Type::COUNT; ++j) {
+            for (size_t k = 0; k < (size_t) Type::COUNT; ++k) {
                 binary_ops[i][j][k] = [&i](Value const& a, Value const& b) -> Value {
                     throw VMInvalidOperation((BinaryOperationType) i, a.type(), b.type());
                 };
+            }
+        }
+    }
+
+    // every equality/inequality, by default, return inequal
+    for (size_t j = 0; j < (size_t) Type::COUNT; ++j) {
+        for (size_t k = 0; k < (size_t) Type::COUNT; ++k) {
+            binary_ops[(size_t) BinaryOperationType::Equality][j][k] = [](Value const&, Value const&) { return Value::createFalse(); };
+            binary_ops[(size_t) BinaryOperationType::Inequality][j][k] = [](Value const&, Value const&) { return Value::createTrue(); };
+        }
+    }
 
 #define BIN_OP(op, t1, t2) binary_ops[(size_t) BinaryOperationType::op][(size_t) Type::t1][(size_t) Type::t2] = [](Value const& b, Value const& a)
 
@@ -23,6 +35,7 @@ static int init_ = []() {
     BIN_OP(Sum, Integer, Float)   { return Value::createFloat((float) a.as_integer() + b.as_float()); };
     BIN_OP(Sum, Float, Integer)   { return Value::createFloat(a.as_float() + (float) b.as_integer()); };
     BIN_OP(Sum, Float, Float)     { return Value::createFloat(a.as_float() + b.as_float()); };
+    BIN_OP(Sum, String, String)   { return Value::createString(a.as_string() + b.as_string()); };
 
     BIN_OP(Subtraction, Integer, Integer) { return Value::createInteger(a.as_integer() - b.as_integer()); };
     BIN_OP(Subtraction, Integer, Float)   { return Value::createFloat((float) a.as_integer() - b.as_float()); };
@@ -48,11 +61,13 @@ static int init_ = []() {
     BIN_OP(Equality, Integer, Float)   { return Value::createIntegerFromBool(std::abs((float) a.as_integer() - b.as_float()) < FLOAT_EPSILON); };
     BIN_OP(Equality, Float, Integer)   { return Value::createIntegerFromBool(std::abs(a.as_float() - (float) b.as_integer()) < FLOAT_EPSILON); };
     BIN_OP(Equality, Float, Float)     { return Value::createIntegerFromBool(std::abs(a.as_float() - b.as_float()) < FLOAT_EPSILON); };
+    BIN_OP(Equality, String, String)   { return Value::createIntegerFromBool(a.as_string() == b.as_string()); };
 
     BIN_OP(Inequality, Integer, Integer) { return Value::createIntegerFromBool(a.as_integer() != b.as_integer()); };
     BIN_OP(Inequality, Integer, Float)   { return Value::createIntegerFromBool(std::abs((float) a.as_integer() - b.as_float()) >= FLOAT_EPSILON); };
     BIN_OP(Inequality, Float, Integer)   { return Value::createIntegerFromBool(std::abs(a.as_float() - (float) b.as_integer()) >= FLOAT_EPSILON); };
     BIN_OP(Inequality, Float, Float)     { return Value::createIntegerFromBool(std::abs(a.as_float() - b.as_float()) >= FLOAT_EPSILON); };
+    BIN_OP(Inequality, String, String)   { return Value::createIntegerFromBool(a.as_string() != b.as_string()); };
 
     BIN_OP(LessThan, Integer, Integer) { return Value::createIntegerFromBool(a.as_integer() < b.as_integer()); };
     BIN_OP(LessThan, Integer, Float)   { return Value::createIntegerFromBool((float) a.as_integer() < b.as_float()); };
diff --git a/src/vm/tests.cc b/src/vm/tests.cc
index 102c447..b147cc7 100644
--- a/src/vm/tests.cc
+++ b/src/vm/tests.cc
@@ -222,6 +222,52 @@ TEST(VM, FloatFloatOperations)
     ASSERT_FLOAT_EQ(test_op("3.2", "3.2", "eq").to_integer(-1), 1);
 }
 
+TEST(VM, StringString)
+{
+    ASSERT_EQ(run(R"(
+        .const
+            0: "Hello"
+            1: "World"
+        .func 0
+            pushc 0
+            pushc 1
+            sum
+            ret
+    )").to_string(-1), "HelloWorld");
+
+    ASSERT_EQ(run(R"(
+        .const
+            0: "Hello"
+            1: "World"
+        .func 0
+            pushc 0
+            pushc 1
+            eq
+            ret
+    )").to_integer(-1), 0);
+
+    ASSERT_EQ(run(R"(
+        .const
+            0: "Hello"
+            1: "Hello"
+        .func 0
+            pushc 0
+            pushc 1
+            eq
+            ret
+    )").to_integer(-1), 1);
+
+    ASSERT_EQ(run(R"(
+        .const
+            0: "Hello"
+        .func 0
+            pushc 0
+            pushi 1
+            eq
+            ret
+    )").to_integer(-1), 0);
+}
+
 int main(int argc, char** argv)
 {
     testing::InitGoogleTest(&argc, argv);
diff --git a/src/vm/value.hh b/src/vm/value.hh
index 0318ecd..65c98ce 100644
--- a/src/vm/value.hh
+++ b/src/vm/value.hh
@@ -28,6 +28,8 @@ public:
     static Value createString(std::string const& str) { return Value(str); }
     static Value createFunctionId(FunctionId f_id) { return Value(Function { f_id }); }
 
+    static Value createFalse() { return createInteger(0); }
+    static Value createTrue() { return createInteger(1); }
     static Value createIntegerFromBool(bool b) { return createInteger(b ? 1 : 0); }
 
     [[nodiscard]] Type type() const;