time-to-botec

README.md (4864B)

---

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 @license Apache-2.0
 
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 Licensed under the Apache License, Version 2.0 (the "License");
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 See the License for the specific language governing permissions and
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 # Find
 
 > Find elements in an array-like object that satisfy a test condition.
 
 <section class="usage">
 
 ## Usage
 
 <!-- eslint-disable stdlib/no-redeclare -->
 
 ```javascript
 var find = require( '@stdlib/utils/find' );
 ```
 
 #### find( arr, \[opts,] clbk )
 
 Finds elements in an array-like object that satisfy a test condition. The function accepts two options: `k` and `returns`.
 
 -   **k**: an `integer` which limits the number of elements returned and whose sign determines the direction in which to search. If set to a negative `integer`, the function searches from the last element to the first element.
 
 -   **returns**: specifies the type of result to return and may be one of three options: `indices`, `values`, `*`.
 
     -   **indices**: indicates to return the element indices of those elements satisfying the search condition.
     -   **values**: indicates to return the element values of those elements satisfying the search condition.
     -   **\***: indicates to return both the element indices and values of those elements satisfying the search condition. The returned result is an `array` of `arrays`, where each sub-array is an index-value pair.
 
 The `callback` is provided three arguments:
 
 -   **element**: the current element
 -   **index**: the current element's index
 -   **array**: the input `array`, `typed array` or `string`
 
 By default, `k` is the length of `arr` and `returns` is set to `indices`.
 
 <!-- eslint-disable stdlib/no-redeclare -->
 
 ```javascript
 var data = [ 30, 20, 50, 60, 10 ];
 
 function greaterThan20( val ) {
     return val > 20;
 }
 
 var vals = find( data, greaterThan20 );
 // returns [ 0, 2, 3 ]
 
 data = 'Hello World';
 function isUpperCase( val ) {
     return /[A-Z]/.test( val );
 }
 
 vals = find( data, isUpperCase );
 // returns [ 0, 6 ]
 ```
 
 To limit the number of results and specify that `values` should be returned,
 
 <!-- eslint-disable stdlib/no-redeclare -->
 
 ```javascript
 var data = [ 30, 20, 50, 60, 10 ];
 
 var opts = {
     'k': 2,
     'returns': 'values'
 };
 
 function condition( val ) {
     return val > 20;
 }
 
 var vals = find( data, opts, condition );
 // returns [ 30, 50 ]
 ```
 
 If no `array` elements satisfy the test condition, the function returns an empty `array`.
 
 <!-- eslint-disable stdlib/no-redeclare -->
 
 ```javascript
 var data = [ 30, 20, 50, 60, 10 ];
 
 var opts = {
     'k': 2,
     'returns': 'values'
 };
 
 function condition( val ) {
     return val > 1000;
 }
 
 var vals = find( data, opts, condition );
 // returns []
 ```
 
 To find the last two values satisfying a search condition,
 
 <!-- eslint-disable stdlib/no-redeclare -->
 
 ```javascript
 var data = [ 30, 20, 50, 60, 10 ];
 
 var opts = {
     'k': -2,
     'returns': 'values'
 };
 
 function condition( val ) {
     return val > 20;
 }
 
 var vals = find( data, opts, condition );
 // returns [ 60, 50 ]
 ```
 
 To explicitly specify that only indices are returned,
 
 <!-- eslint-disable stdlib/no-redeclare -->
 
 ```javascript
 var data = [ 30, 20, 50, 60, 10 ];
 
 var opts = {
     'k': -2,
     'returns': 'indices'
 };
 
 function condition( val ) {
     return val > 20;
 }
 
 var vals = find( data, opts, condition );
 // returns [ 3, 2 ]
 ```
 
 And to return both indices and values as index-value pairs,
 
 <!-- eslint-disable stdlib/no-redeclare -->
 
 ```javascript
 var data = [ 30, 20, 50, 60, 10 ];
 
 var opts = {
     'k': -2,
     'returns': '*'
 };
 
 function condition( val ) {
     return val > 20;
 }
 
 var vals = find( data, opts, condition );
 // returns [ [3, 60], [2, 50] ]
 ```
 
 </section>
 
 <!-- /.usage -->
 
 <section class="examples">
 
 ## Examples
 
 <!-- eslint-disable stdlib/no-redeclare -->
 
 <!-- eslint no-undef: "error" -->
 
 ```javascript
 var round = require( '@stdlib/math/base/special/round' );
 var randu = require( '@stdlib/random/base/randu' );
 var find = require( '@stdlib/utils/find' );
 
 var data;
 var opts;
 var vals;
 var i;
 
 // Simulate the data...
 data = new Array( 100 );
 
 for ( i = 0; i < data.length; i++ ) {
     data[ i ] = round( randu*100 );
 }
 
 // Find the first 10 values greater than 25...
 opts = {
     'k': 10,
     'returns': '*'
 };
 
 function condition( val ) {
     return val > 25;
 }
 
 vals = find( data, opts, condition );
 console.log( vals.join( '\n' ) );
 ```
 
 </section>
 
 <!-- /.examples -->
 
 <section class="links">
 
 </section>
 
 <!-- /.links -->