小米公司JavaScript面试题

/**
* 第一题
* @param func
* @param times
* @param wait
* @returns {repeatImpl}
*/
function repeat (func, times, wait) {
//不用匿名函数是为了方便调试
function repeatImpl(){
var handle,
_arguments = arguments,
i = 0;
handle = setInterval(function(){
i = i + 1;
//到达指定次数取消定时器
if(i === times){
clearInterval(handle);
return;
}
func.apply(null, _arguments);
},wait);
}
return repeatImpl;
}
//测试用例
var repeatFun = repeat(alert, 4, 3000);
repeatFun("hellworld");
/**
* 第二题
* @returns {string}
*/
function stringconcat(){
var result = [];
stringconcat.merge.call(null, result, arguments);
return result.join("+");
}
stringconcat.prefix = function(){
var _arguments = [],
_this = this;
_this.merge.call(null, _arguments, arguments);
return function(){
var _args = _arguments.slice(0);
_this.merge.call(null, _args, arguments);
return _this.apply(null, _args);
};
};
stringconcat.merge = function(array, arrayLike){
var i = 0;
for(i = 0; i < arrayLike.length; i++){
array.push(arrayLike[i]);
}
}
//测试用例
var result1 = stringconcat("a", "b"); //result1 = "a+b"
var result3 = stringconcat("c", "d"); //result1 = "a+b"
var stringconcatWithPrefix = stringconcat.prefix("hellworld");
var stringconcatWithPrefix1 = stringconcat.prefix("hellworld1");
var result2 = stringconcatWithPrefix("a", "b"); //result2 = "hellworld+a+b"
var result4 = stringconcatWithPrefix1("c", "d"); //result2 = "hellworld+a+b"
alert(result1);
alert(result2);
alert(result3);
alert(result4);