数组prototype添加函数呢，采用回调判定函数内容

1、解决方案

Array.prototype.all = function (p) { return this.filter(p).length == this.length; };

Array.prototype.none = function (p) { return this.filter(p).length == 0; };

Array.prototype.any = function (p) { return this.filter(p).length > 0; };

 

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Array.prototype.all = function(p) { var trueFalse; for (var i = 0; i < this.length; i++) { trueFalse = p(this[i]); if (!trueFalse) { return false; } } return true; };

Array.prototype.none = function(p) { var trueFalse; for (var i = 0; i < this.length; i++) { trueFalse = p(this[i]); if (trueFalse) { return false; } } return true; };

Array.prototype.any = function(p) { var trueFalse; for (var i = 0; i < this.length; i++) { trueFalse = p(this[i]); if (trueFalse) { return true; } } return false; };

 

 

2、题目

Array.prototype.all = function (p) {
// TODO: Implement this function
};

Array.prototype.none = function (p) {
// TODO: Implement this function
return null;
};

Array.prototype.any = function (p) {
// TODO: Implement this function
return null;
};

 

function isGreaterThanZero (num) {
return num > 0;
}

function isLessThanZero (num) {
return num < 0;
}

Test.expect([1, 2, 3].all(isGreaterThanZero), 'All are greater than zero');
Test.expect(![-1, 0, 2].all(isGreaterThanZero), 'One is less than zero');

Test.expect(![-1, 2, 3].none(isLessThanZero), 'One is less than zero');
Test.expect([-1, -2, -3].none(isGreaterThanZero), 'None are greater than zero');