Question

How can I do a query to an array javascript, for example I want to find all names that begin with A, an then show all information

Name”:”Albert”,”age”:”14″
Name”:”Alison”,”age”:”14″

this is my array json:

var house = [{"Name":"Jason","age":"43"},
{"Name":"Albert","age":"14"},
{"Name":"Luck","age":"14"},
{"Name":"Alison","age":"14"},
{"Name":"Tom","age":"12"}]

Answer 1

You can filter an array, to collect the elements with an ‘A’ name, then forEach or map the matches to a new array of property names and values

house.filter(function(itm){
    return itm.Name.charAt(0)== 'A';
}).map(function(o){
    var A= [];
    for(var p in o){
        if(o.hasOwnProperty(p)){
            A.push(p+':'+o[p]);
        }
    }
    return A;
}).join('\n');

/* returned value: (String)*/

Name:Albert,age:14
Name:Alison,age:14

If you need a shim:

(function(){
    var A= Array.prototype;
    if(!A.filter)   A.filter= function(fun, scope){
        var T= this, A= [], i= 0, itm, L= T.length;
        if(typeof fun== 'function'){
            while(i<L){
                if(i in T){
                    itm= T[i];
                    if(fun.call(scope, itm, i, T)) A[A.length]= itm;
                }
                ++i;
            }
        }
        return A;
    }
    if(!A.map) A.map= function(fun, scope){
        var T= this, L= T.length, A= Array(L), i= 0;
        if(typeof fun== 'function'){
            while(i<L){
                if(i in T){
                    A[i]= fun.call(scope, T[i], i, T);
                }
                ++i;
            }
            return A;
        }
    }
}
})();