数组元素判断算法挑战
问题:
完善编辑器中的every函数，如果集合(collection)中的所有对象都存在对应的属性(第二个参数)，并且属性(第二个参数)对应的值为真。函数返回ture。反之，返回false。
记住：您可以通过点符号或[]符号来访问对象属性。
要求：
every([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy", "sex": "male"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex") 应该返回 true。
every([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex") 应该返回 false。
every([{"user": "Tinky-Winky", "sex": "male", "age": 0}, {"user": "Dipsy", "sex": "male", "age": 3}, {"user": "Laa-Laa", "sex": "female", "age": 5}, {"user": "Po", "sex": "female", "age": 4}], "age") 应该返回 false。
every([{"name": "Pete", "onBoat": true}, {"name": "Repeat", "onBoat": true}, {"name": "FastFoward", "onBoat": null}], "onBoat") 应该返回 false
every([{"name": "Pete", "onBoat": true}, {"name": "Repeat", "onBoat": true, "alias": "Repete"}, {"name": "FastFoward", "onBoat": true}], "onBoat") 应该返回 true
every([{"single": "yes"}], "single") 应该返回 true
every([{"single": ""}, {"single": "double"}], "single") 应该返回 false
every([{"single": "double"}, {"single": undefined}], "single") 应该返回 false
every([{"single": "double"}, {"single": NaN}], "single") 应该返回 false
问题答案：
function every(collection, pre) {
var bCheck=true;
for(var i in collection)
{ if(!collection[i][pre]){ bCheck=false; } }
return bCheck;
}
every([{"user": "Tinky-Winky", "sex": "male"}, {"user": "Dipsy", "sex": "male"}, {"user": "Laa-Laa", "sex": "female"}, {"user": "Po", "sex": "female"}], "sex");