countOccurrencesFilter() javascript code example

Example 1: javascript count number of occurrences in array of objects

var result = array.reduce( (acc, o) => (acc[o.name] = (acc[o.name] || 0)+1, acc), {} );

Example 2: javascript count number of occurrences in array of objects

var array =
    [
        {"name":"abc","age":20}
        {"name":"abc","age":20}
        {"name":"abc","age":20}
        {"name":"xyz","age":21}
        {"name":"xyz","age":21}
    ]