sum of array with the save id javascript
var a = [];
a.push({taxid : 1, tax_name: 'VAT', tax_value:'25.00'});
a.push({taxid : 2, tax_name: 'Service Tax', tax_value:'20.00'});
a.push({taxid : 1, tax_name: 'VAT', tax_value:'25.00'});
a.push({taxid : 2, tax_name: 'Service Tax', tax_value:'75.00'});
//Sum up all the same taxid tax_value
var temp = {};
a.forEach(function(obj){
if(!temp[obj.taxid]){
temp[obj.taxid] = obj.tax_value;
} else {
temp[obj.taxid] = Number(temp[obj.taxid]) + Number(obj.tax_value);
}
});
//Format the data into desired output
var result = [];
for(var key in temp){
result.push({
taxid: key,
tax_value: temp[key]
})
}
console.log(result)