Most-used Lodash functions in Peaka

In JEXL, we can use all lodash functions. This article provides a list of the most frequently used among them.

If you want to see more lodash functions, check out this article.

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isArray(value)

Checks if value is classified as an Array object.

• value is required.

    {{ isArray([1, 2, 3]) }}
    // => true

    {{ isArray('text') }}
    // => false

​

concat(array, [values])

Creates a new array concatenating array with any additional arrays and/or values.

• values and array are required.

    {{ concat([1], 2, [3], [[4]]) }}
    // => [1, 2, 3, [4]]

​

indexOf(array, value, [fromIndex=0])

Gets the index where the first occurrence of value is found in array. If fromIndex is negative, it’s used as the offset from the end of array.

• array and value is required.
• array (Array): The array to inspect.
• value (*): The value to search for.
• [fromIndex=0] (number): The index to search from.

    {{ _.indexOf([1, 2, 1, 2], 2) }}
    // => 1

    // Search from the `fromIndex`.
    {{ indexOf([1, 2, 1, 2], 2, 2) }}
    // => 3

​

reverse(array)

Reverses array so that the first element becomes the last, the second element becomes the second to last, and so on.

• array is required.

    {{ reverse([1, 2, 3]) }}
    // => [3, 2, 1]

​

slice(array, [start=0], [end=array.length])

Creates a slice of array from start up to, but not including, the end.

• array (Array): The array to slice.
• [start=0] (number): The start position.
• [end=array.length] (number): The end position.

    {{ slice([1,2,3,4,5],2,4)}}
    // [3,4]

​

without(array, [values])

Creates an array excluding all given values.

• array (Array): The array to inspect.
• [values]: The values to exclude.

    {{ without([2, 1, 2, 3], 1, 2) }}
    // => [3]

​

filter(collection, filterItems)

Iterates over elements of collection, returning an array of all elements predicate returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).

• collection (Array|Object): The collection to iterate over.
• filterItems: The items you want to filter by them.

{{
    filter(
      [
        { user: "barney", age: 36, active: true },
        { user: "fred", age: 40, active: false },
      ],
      { age: 36, active: true }
    );
}}
// => ['barney']

{{
    filter(
      [
        { user: "barney", age: 36, active: true },
        { user: "fred", age: 40, active: false },
      ],
      ["active", false]
    );
}}
// => ['fred']

​

eq(value, other)

Compares value and other, return true or false according to they equals each other or not.

• value and other are required and can be any type.

    {{ eq( 1, 1 ) }}
    // => true

    {{ eq( 1, 'some text' ) }}
    // => false

​

sum(array)

Computes the sum of the values in array.

• array is required and includes items which are number tpye.

    {{ sum([4, 2, 8, 6]) }}
    // => 20

### max(array)

Computes the maximum value of array. If array is empty or falsey, undefined is returned.

• array is required.

    {{ max([4, 2, 8, 6]) }}
    // => 8

    {{ max([]) }}
    // => undefined

​

get(object, path, [defaultValue])

Gets the value at path of object. If the resolved value is undefined, the defaultValue is returned in its place.

• object (Object): The object to query.
• path (Array|string): The path of the property to get.
• [defaultValue] (*): The value returned for undefined resolved values.

    {{
        get({ a: [{ b: { c: 3 } }] }), "a[0].b.c";
    }}
    // => 3

    {{
        get({ a: [{ b: { c: 3 } }] }),['a', '0', 'b', 'c'];
    }}
    // => 3

​

hasIn(object, path)

Checks if path is a direct or inherited property of object.

• object and path are required.

    {{ hasIn({ a: { b:2 }}, 'a') }}
    // => true

    {{ hasIn({ a: { b:2 }}, 'a.b') }}
    // => true

    {{  hasIn({ a: { b:2 }}, ['a', 'b']) }}
    // => true

    {{  hasIn({ a: { b:2 }}, 'b') }}
    // => false