问求和嵌套数组

EN

[{BenefitType:'401k',
   Beneficiaries: [{Name: 'PersonA', Percentage: 20},
                   {Name: 'PersonB', Percentage: 30},
                   {Name: 'PersonC', Percentage: 50}]
},
 {BenefitType:'IRA',
   Beneficiaries: [{Name: 'PersonA', Percentage: 15},
                   {Name: 'PersonB', Percentage: 45},
                   {Name: 'PersonC', Percentage: 40}]
}];

var myTotal = 0;

for(var i = 0; i < data.benefit_type.length; i++) {
    for(var j=0; j < data.benefit_type[i].beneficiaries.length; j++) {
        myTotal += parseInt(data.benefit_type[i].beneficiaries[j].percentage); 
        data.benefit_type[i].percent_total = myTotal;

    } 
}