程序代写代做代考 interpreter Safari 浏览器

Safari 浏览器

Testing Your Interpreter, Part 3

Test 1: A main with code inside. This code should return 10.

function main() {
var x = 10;
var y = 20;
var z = 30;
var min = 0;

if (x < y) min = x; else min = y; if (min > z)
min = z;
return min;
}

Test 2: A function that uses global variables. This code should return 14.

var x = 4;
var y = 6 + x;

function main() {
return x + y;
}

Test 3: A function that changes global variables. This code should return 45.

var x = 1;
var y = 10;
var r = 0;

var x = 10;
var y = 20;
var z = 30;

var min1 = min(x,y,z);
var min2 = min(z,y,x);

function main() {
var min3 = min(y,z,x);

if (min1 == min3)
if (min1 == min2)
if (min2 == min3)
return 1;
return 0;
}

Test 6: Verifying that your code uses static scoping instead of dynamic scoping. This code should return
115.

var a = 10;
var b = 20;

function bmethod() {
var b = 30;
return a + b;
}

function cmethod() {
var a = 40;
return bmethod() + a + b;
}

function main () {
var b = 5;
return cmethod() + a + b;
}

Test 7: Boolean parameters and return values. This code should return true.

function minmax(a, b, min) {
if (min && a < b || !min && a > b)
return true;
else
return false;
}

function main() {
return (minmax(10, 100, true) && minmax(5, 3, false));
}

Test 8: Multiple function calls in an expression. This code should return 20.

function fact(n) {
var f = 1;
while (n > 1) {
f = f * n;
n = n – 1;
}
return f;
}

function binom(a, b) {
var val = fact(a) / (fact(b) * fact(a-b));
return val;
}

function main() {
return binom(6,3);
}

Test 9: A function call in the parameter of a function. This code should return 24.

function fact(n) {
var r = 1;
while (n > 1) {
r = r * n;
n = n – 1;
}
return r;
}

function main() {
return fact(fact(3) – fact(2));
}

Test 10: A function call that ignores the return value. This code should return 2.

var count = 0;

function f(a,b) {
count = count + 1;
a = a + b;
return a;
}

function main() {
f(1, 2);
f(3, 4);
return count;
}

Test 11: A function without a return statement. This code should return 35.

var x = 0;
var y = 0;

function setx(a) {
x = a;
}

function sety(b) {
y = b;
}

function main() {
setx(5);
sety(7);
return x * y;
}

Test 12: Mismatched parameters and arguments. This code should give an error.

function f(a) {
return a*a;
}

function main() {
return f(10, 11, 12);
}

Test 13: Functions inside functions. This code should return 90.

function main() {
function h() {
return 10;
}

function g() {
return 100;
}

return g() – h();
}

Test 14: Functions inside functions accessing variables outside. This code should return 69.

function collatz(n) {
var counteven = 0;
var countodd = 0;

function evenstep(n) {
counteven = counteven + 1;
return n / 2;
}

function oddstep(n) {
countodd = countodd + 1;
return 3 * n + 1;
}

while (n != 1) {
if (n % 2 == 0)
n = evenstep(n);
else
n = oddstep(n);
}
return counteven + countodd;
}

function main() {
return collatz(111);
}

Test 15: Functions inside functions with variables of the same name. Thus code should return 87.

function f(n) {
var a;
var b;
var c;

a = 2 * n;
b = n – 10;

function g(x) {
var a;
a = x + 1;
b = 100;
return a;
}

if (b == 0)
c = g(a);
else
c = a / b;
return a + b + c;
}

function main() {
var x = f(10);
var y = f(20);

return x – y;
}

Test 16: Functions inside functions inside functions. This code should return 64.

function main() {
var result;
var base;

function getpow(a) {
var x;

function setanswer(n) {
result = n;
}

function recurse(m) {
if (m > 0) {
x = x * base;
recurse(m-1);
}
else
setanswer(x);
}

x = 1;
recurse(a);
}
base = 2;
getpow(6);
return result;
}

Test 17: Functions inside functions accessing out of scope variables. This code should return an error
with b out of scope.

function f(x) {
function g(x) {
var b;
b = x;
return 0;
}

function h(x) {
b = x;
return 1;
}

return g(x) + h(x);
}

function main() {
return f(10);
}

Test 18: try/catch finally, but no exception thrown. This code should return 125.

function divide(x, y) {
if (y == 0)
throw y;
return x / y;
}

function main() {
var x;

try {
x = divide(10, 5) * 10;
x = x + divide(5, 1);
}
catch(e) {
x = e;
}
finally {
x = x + 100;
}
return x;
}

Test 19: Throwing an exception inside a function. This code should return 100.

function divide(x, y) {
if (y == 0)
throw y;
return x / y;
}

function main() {
var x;

try {
x = divide(10, 5) * 10;
x = x + divide(5, 0);
}
catch(e) {
x = e;
}
finally {
x = x + 100;
}
return x;
}

Test 20: Throwing an exception from a function. This code should return 2000400.

function divide(x, y) {
if (y == 0)
throw 1000000;
return x / y;
}

function main() {
var x = 0;
var j = 1;

try {
while (j >= 0) {
var i = 10;
while (i >= 0) {
try {
x = x + divide(10*i, i);
}
catch(e) {
x = x + divide(e, j);
}
i = i – 1;
}
j = j – 1;
}
}
catch (e2) {
x = x * 2;
}
return x;
}

Additional Tests For Those Doing the Extra Challenge

Test 21: Call-by-reference test. This code should return 3421.

function swap1(x, y) {
var temp = x;
x = y;
y = temp;
}

function swap2(&x, &y) {
var temp = x;
x = y;
y = temp;
}

function main() {
var a = 1;
var b = 2;
swap1(a,b);
var c = 3;
var d = 4;
swap2(c,d);
return a + 10*b + 100*c + 1000*d;
}

Test 22: Assignment side effects with function calls. This code should return 20332.

var x;

function f(a,b) {
return a * 100 + b;
}

function fib(f) {
var last = 0;
var last1 = 1;

while (f > 0) {
f = f – 1;
var temp = last1 + last;
last = last1;
last1 = temp;
}
return last;
}

function main() {
var y;
var z = f(x = fib(3), y = fib(4));
return z * 100 + y * 10 + x;
}

Test 23: Mixture of call-by-value and call-by-reference. This code should return 21.

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