[{"A":"a","B":"b"},{"A":"a","B":"b"},{"C":"c"}]

    var arr = [{"A":"a","B":"b"},{"A":"a","B":"b"},{"C":"c"}] ;
    for(var i=0;i<3;i++)
    {
        document.write(arr[i].A + '\n');
    }

------解决方案--------------------
JScript code

// 从数组中取出所有包含属性A的对象
var array = [{ "A": "a", "B": "b" }, { "A": "a", "B": "b" }, { "C": "c"}];
var result = $.grep(array, function (n, i) {
    for (var key in n) {
        if (key == "A") {
            return true;
        }

        continue;
    }
});

//result = [{ "A": "a", "B": "b" }, { "A": "a", "B": "b" }]

------解决方案--------------------
JScript code
Array.prototype.isHas=function (value){
    var max=this.length,res=false;
    if(max==0){return false};
    for(var i=0;i<max;i++){
        for(var name in this[i]){
            if(name==value){
                res=true;
                break;
            }
        };
        if(res){break}
    };
    return res;
};
var arr = [{ "A": "a", "B": "b" }, { "C": "a", "D": "b" }, { "e": "c"}];
var str=arr.isHas("A")?'存在':'不存在';
alert(str)

------解决方案--------------------
如果你的数组里面只是对象 比较容易
JScript code
var arrTest = [{"A":"a","B":"b"},{"A":"a","B":"b"},{"C":"c"}];
    function isIncludeA(arrArr , sEqu){
      if(arrArr instanceof Array){
          var oObj = null;
          var arrResult = new Array();
          for(var i = 0; i < arrArr.length; i++){
              oObj = arrArr[i];
              if(oObj instanceof Object){
                  for(var prop in oObj){
                      if(oObj[prop] == sEqu){
                          arrResult.push(oObj[prop]);
                      }
                  }
              }
          }
          return arrResult.length == 0 ? "没有匹配项" : ("匹配项个数:" + arrResult.length);
      }
    }
    
    window.onload = function(){
        var result = isIncludeA(arrTest , "A");
        alert(result);
    };

------解决方案--------------------
也没什么问题。只是写死了，结果返回不明确。思路是没有问题的

JScript code
Array.prototype.isHas=function (a){
    if(this.length==0){return false};
    for(var i=0;i<this.length;i++){
        if(this[i][a]){return true}
    }
};
var arr = [{ "A": "a", "B": "b" }, { "C": "a", "D": "b" }, { "e": "c"}];
var str=arr.isHas("f")?'存在':'不存在';
alert(str);

------解决方案--------------------
判断对象数组里每个对象是否含有指定属性

   var arr = [{"theforever_csdn":"a","B":"b"},{"theforever_csdn":"a","B":"b"},{"碧海情天":"c"}] ;
   for(var i=0;i<arr.length;i++)