Modern PHP: Difference between revisions
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yield 3; | yield 3; | ||
} | } | ||
Generators are forward-only iterators, i.e. you can only request the next value, not the previous, next but one etc. They are useful for iterating sequential data sets such as reading a file line by line (in order). | |||
== Useful dependencies == | == Useful dependencies == | ||
Revision as of 20:39, 10 April 2018
Generators
Generators are similar to iterators that calculate their values on demand, thus potentially using fewer resources. They can be created using the yield keyword, e.g.:
function my_generator()
{
yield 1;
yield 2;
yield 3;
}
Generators are forward-only iterators, i.e. you can only request the next value, not the previous, next but one etc. They are useful for iterating sequential data sets such as reading a file line by line (in order).