@stdlib/utils/any-in-by/README.md

Standard utilities.

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# anyInBy

> Test whether at least one property in an object passes a test implemented by a predicate function.

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## Usage

```javascript
var anyInBy = require( '@stdlib/utils/any-in-by' );
```

#### anyInBy( object, predicate\[, thisArg ] )

Tests whether at least one property in an `object` passes a test implemented by a `predicate` function.

```javascript
function isNegative( value ) {
    return ( value < 0 );
}

var obj = {
    'a': 1,
    'b': 2,
    'c': -1
};

var bool = anyInBy( obj, isNegative );
// returns true
```

If a `predicate` function returns a truthy value, the function **immediately** returns `true`.

```javascript
function isPositive( value ) {
    if ( value < 0 ) {
        throw new Error( 'should never reach this line' );
    }
    return ( value > 0 );
}

var obj = {
    'a': 1,
    'b': -2,
    'c': 3
};

var bool = anyInBy( obj, isPositive );
// returns true
```

The invoked `function` is provided three arguments:

-   **value**: property value.
-   **key**: property key.
-   **object**: input object.

To set the function execution context, provide a `thisArg`.

```javascript
function sum( value ) {
    this.sum += value;
    this.count += 1;
    return ( value < 0 );
}

var obj = {
    'a': 1,
    'b': 2,
    'c': 3,
    'd': -4
};

var context = {
    'sum': 0,
    'count': 0
};

var bool = anyInBy( obj, sum, context );
// returns true

var mean = context.sum / context.count;
// returns 0.5
```

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## Notes

-   The `obj` object may contain own properties as well as inherited properties from its prototype chain.

-   If provided an empty object, the function returns `false`.

    ```javascript
    function alwaysTrue() {
        return true;
    }
    var bool = anyInBy( {}, alwaysTrue );
    // returns false
    ```

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## Examples

<!-- eslint no-undef: "error" -->

```javascript
var randu = require( '@stdlib/random/base/randu' );
var anyInBy = require( '@stdlib/utils/any-in-by' );

function threshold( value ) {
    return ( value > 0.95 );
}

var bool;
var obj = {};
var i;

for ( i = 0; i < 100; i++ ) {
    obj[i] = randu();
}

bool = anyInBy( obj, threshold );
// returns <boolean>
```

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