Two dimensional arrays are everywhere. For instance, all data coming from a database table would probably find its way to you as a two dimensional array. Here is an example of one:
[
{ "id":1, "first_name":"Tinna", "last_name":"Donne", }
{ "id":2, "first_name":"Joanne", "last_name":"Smith", }
]
Working with 2 dimensional arrays in JavaScript is not the nicest of experience. The standard Array functions do not provide anything out of the box to help with.
Here are a few functions, attached to the Array prototype, which can make your life easier, when sorting through two dimensional arrays.
Array.prototype.selectOne = function (where) {
var filtered = this.selectWhere(where);
if (filtered.length > 0) {
return filtered[0];
}
return null;
};
Array.prototype.selectWhere = function (where) {
var columnName = where[0];
var comparator = where[1];
var compareValue = where[2];
var filtered = [];for (var i = 0; i < this.length; i++) {
var row = this[i];
if (row[columnName] == compareValue) { // Leave as is, do not use "==="
filtered.push(row);
}
}
return filtered;
};
Here is an example how to use:
// Get the person with ID=2 var person = people.selectOne(['id','=','2']);// Get the person with last name Smith var person = people.selectOne(['last_name','=','Smith']);// Get all the people whose first name is Joanne var joannes = people.selectWhere(['last_name','=','Smith']);