<ul data-eligibleForWebStory="true"><li>JavaScript reduce method transforms arrays into single values by calling a callback on each array item with an accumulator.</li><li>The reduce signature includes parameters like accumulator, currentValue, index, array, and initialValue.</li><li>Examples include summing numbers, building objects from arrays, and chaining methods like filter, map, and reduce.</li><li>Reduce can be used for various tasks like flattening arrays, counting occurrences, and promise chaining in JavaScript.</li></ul>

Understanding JavaScript reduce

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