How do you return objects in an array if it contain specific key-value pairs?
I need to return it if it has all key value pairs given, not just one.
for example,
This function with the array of objects as the 1st argument, and an object with given key value pairs as the 2nd argument
whatIsInAName([{ "a": 1, "b": 2 }, { "a": 1 }, { "a": 1, "b": 2, "c": 2 }], { "a": 1, "b": 2 });
should return
[{ "a": 1, "b": 2 }, { "a": 1, "b": 2, "c": 2 }]
You can do this with filter() and every().
function whatIsInAName(a, b) {
return a.filter(function(e) {
return Object.keys(b).every(function(c) {
return e[c] == b[c]
})
})
}
console.log(whatIsInAName([{ "a": 1, "b": 2 }, { "a": 1 }, { "a": 1, "b": 2, "c": 2 }], { "a": 1, "b": 2 })) 
Use underscore.js. It's simple.
function whatIsInAName(a, b){
return _.where(a, b);
}
var data = whatIsInAName([{ "a": 1, "b": 2 }, { "a": 1 }, { "a": 1, "b": 2, "c": 2 }], { "a": 1, "b": 2 });
console.log(data);<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>Use Array#filter method with Array#every method.
function whatIsInAName(arr, obj) {
// get the keys array
var keys = Object.keys(obj);
// iterate over the array
return arr.filter(function(o) {
// iterate over the key array and check every property
// is present in the object with the same value
return keys.every(function(k) {
return obj[k] === o[k];
})
})
}
console.log(whatIsInAName([{ "a": 1, "b": 2 }, { "a": 1 }, { "a": 1, "b": 2, "c": 2 }], { "a": 1, "b": 2 }));You could filter the array with a check for the pattern's key and values.
function whatIsInAName(array, pattern) {
var keys = Object.keys(pattern);
return array.filter(function (o) {
return keys.every(function (k) {
return pattern[k] === o[k];
});
});
}
console.log(whatIsInAName([{ "a": 1, "b": 2 }, { "a": 1 }, { "a": 1, "b": 2, "c": 2 }], { "a": 1, "b": 2 }));
pattern[k] = o[k] this is an asignment, no comparison ;) and I'd remove/extract this part Object.keys(pattern) out of the loop
has all key value pairs?