Introducing every method
if you want to check if all elements in the array are passing a condition you can use every method. every accepts a callback which should return a boolean to indicate a pass or a fail.
const todos = [
{
id: 1,
label: "Todo 1",
is_completed: true
},
{
id: 2,
label: "Todo 2",
is_completed: true
},
{
id: 3,
label: "Todo 3",
is_completed: true
}
];
// returns true because all todos are completed
todos.every((todo) => todo.is_completed);every returns true if all elements are passing a condition. Otherwise it returns false.
const todos = [
{
id: 1,
label: "Todo 1",
is_completed: true
},
{
id: 2,
label: "Todo 2",
is_completed: false
},
{
id: 3,
label: "Todo 3",
is_completed: true
}
];
// returns false because not all todos are completed
todos.every((todo) => todo.is_completed);Exploring some method
Another similar method is some which iterates through the array and accepts a callback. It returns true if at least one element is passing a condition.
const todos = [
{
id: 1,
label: "Todo 1",
is_completed: false
},
{
id: 2,
label: "Todo 2",
is_completed: false
},
{
id: 3,
label: "Todo 3",
is_completed: true
}
];
// returns true because at least one todo is completed
todos.some((todo) => todo.is_completed);
