I have the following dataset
data=[{name: "hk", age:21, gender:"M"}, {name: "kk", age:31, gender:"M"},{name: "tk", age:11, gender:"F"}]
How could I test whether or not there is a person name "hk" and index of the found object.
I have checked with the following code, but it does not work.
data.hasOwnProperty("hk")
You'd have to iterate through the array and check each object for that
function hasName(prop, value, data) {
return data.some(function(obj) {
return prop in obj && obj[prop] === value;
});
}
if you want to return the index instead, one has to use a loop that keeps track of the index, something like forEach instead
function hasName(prop, value, data) {
var result = -1;
data.forEach(function(obj, index) {
if (prop in obj && obj[prop] === value) {
result = index;
return false;
}
});
return result;
}
Try (like indexOf):
var data=[{name: "hk", age:21, gender:"M"}, {name: "kk", age:31, gender:"M"},{name: "tk", age:11, gender:"F"}]
function exists(name){
var item, i = 0;
while(item = data[i++])
if(item.name == name) return --i
return -1
}
alert("Exists tk? - Index: " + exists("tk")); //-1: not exists
some in a array, I used a loop since some still not supported in some browsers. It is even fasterreturn index: To check if not exists, the value returns -1. Equivale to indexOf
for (var i = 0, n = data.length; i != n; ++i) operates faster than evaluating the array element each time.