jsonarray.length表现得很模糊

Question

我有一个返回jsonarray的函数。

1）我执行了aarray.length，它给出了x

2）我向数组添加了一个JSONelement

3）我再次执行thatarray.length（有时x和x + 1）。这个步骤是在一个完成的 单独的函数和我存储结果的变量在每个函数的顶部单独声明，以消除全局事物

我怀疑Jsonarray.length可能是异步调用

如果是异步调用，如何等到达到结果

我正在通过茉莉花进行检查

提前致谢

代码：

it("getEntities", function() {
    var no_of_entities;
    var metaService = new MetadataService(true);
    fixture = metaService.getMetadataProvider();
    function successCallback(response) {
    if (response !== null && response !== undefined) {
        saas.print("getEntities:successcallback");
            no_of_entities = response.length;
            if (response.length !== null && response.length > 0) {
                test_entityName = response[0]["name"];
                saas.print("response:"+JSON.stringify(response));
                saas.print("--"+no_of_entities);
                }
            flag = true;
        }
    }
    function errorCallback(errror) {
        saas.print("getEntities:errorcallback " + errror.errorCode + ":"
                + errror.errorMsg);
    }
    runs(function() {
        fixture.getEntities(session_token, successCallback,
                errorCallback);
    });
    waitsFor(function() {
        return flag;
    }, duration);

    runs(function() {
        expect(flag).toBe(true);
        expect(test_entityName).toBeDefined();
        expect(test_entityName).not.toBe(null);
        expect(no_of_entities).toEqual(testconstants.TOTAL_ENTITIES_FROM_CRM_IMPORTED);
    });
});

//author aditya
//creation of custom table for enterprisedb
it("createCustomTableForEnterpriseDB", function() {
    function successCallback(response) {    
        if (response !== null && response !== undefined) {
        saas.print("createCustomTableForEnterpriseDB:successcallback");
            flag = true;
            saas.print("response:"+JSON.stringify(response));
                                                        }
                                        }

    function errorcallback(error)
    {
    saas.print("createCustomTableForEnterpriseDB:errorcallback");
    saas.print("Error code:"+error.errorCode+" errorMessage:"+error.errorMsg);
    }
    runs(function() {
        var metadata = new MetaData();
        metadata.createCustomTable(session_token,successCallback,errorcallback);        
                    });
    waitsFor(function() {
            return flag;
    },duration);
    runs(function() {
        expect(flag).toBe(true);
        });
});


//If custom table is created additional table should come in the no of entities
it("getEntitiesAfterCustomTableCreation", function() {
    var no_of_entities;
    var metaService = new MetadataService(true);
    fixture = metaService.getMetadataProvider();
    function successCallback(response) {
    saas.print("getEntitiesAfterCustomTableCreation:successCallback");
        if (response !== null && response !== undefined) {
            flag = true;
            saas.print("response:"+JSON.stringify(response));
            no_of_entities = response.length;
            saas.print("--"+no_of_entities);
            }
            }
    function errorCallback(error)
    {
    saas.print("getEntitiesAfterCustomTableCreation:errorCallback");
    saas.print(error.errorCode+" "+error.errorMsg);
    }
    runs(function() {
        fixture.getEntities(session_token, successCallback,
                errorCallback);
    });
    waitsFor(function() {
        return flag;
    }, duration);

    runs(function() {
        expect(flag).toBe(true);
        expect(test_entityName).toBeDefined();
        expect(test_entityName).not.toBe(null);
//expect(no_of_entities).toEqual(testconstants.TOTAL_ENTITIES_FROM_CRM_IMPORTED+1);
    });
});