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// Singleton
function f() {
var res = 0;
for (var i=0; i<500; i++)
res += ("abcd" in Math);
return res;
}
assertEq(f(), 0);
Math.abcd = 3;
assertEq(f(), 500);
delete Math.abcd;
assertEq(f(), 0);
// Non-singleton
function O(x) { if (x) this.x = 1; }
var arr = [];
for (var i=0; i<4; i++)
arr.push(new O(i % 2));
function g(arr) {
var res = 0;
for (var i=0; i<500; i++) {
var o = arr[i % arr.length];
res += "x" in o;
res += "abcd" in o;
}
return res;
}
assertEq(g(arr), 250);
arr[0].abcd = 3;
assertEq(g(arr), 375);
function testPrimitive() {
var x = 7;
var c = 0;
for (var i=0; i<5; i++) {
try {
"z" in x;
} catch(e) { c++; }
}
assertEq(c, 5);
}
testPrimitive();