How to use the reduce function from lodash
Find comprehensive JavaScript lodash.reduce code examples handpicked from public code repositorys.
lodash.reduce is a JavaScript function that iterates over elements of a collection and returns a single value by performing an operation on each element.
148 149 150 151 152 153 154 155 156 157
encoding: 'utf8' }, (err, stdout, stderr) => { if (err) { // Only exit with an error if we have critical npm errors for 2nd level inside const errors = _.split(stderr, '\n'); const failed = _.reduce(errors, (failed, error) => { if (failed) { return true; } return !_.isEmpty(error) && !_.some(ignoredNpmErrors, ignoredError => _.startsWith(error, `npm ERR! ${ignoredError.npmError}`));
4545 4546 4547 4548 4549 4550 4551 4552 4553 4554
* @param {*} [accumulator] Initial value of the accumulator. * @param {*} [thisArg] The `this` binding of `callback`. * @returns {*} Returns the accumulated value. * @example * * var sum = _.reduce([1, 2, 3], function(sum, num) { * return sum + num; * }); * // => 6 *
+ 3 other calls in file
How does lodash.reduce work?
lodash.reduce
takes three arguments: the collection to iterate over, a function that defines the operation to perform on each element, and an optional initial value.
The function is called for each element in the collection, passing in four arguments: the accumulated value (or the initial value, if provided), the current element, the index of the current element, and the entire collection. The function then returns the updated accumulated value.
If an initial value is provided, the first call to the function will use it as the accumulated value. If no initial value is provided, the first call to the function will use the first element of the collection as the accumulated value.
After all elements have been processed, the final accumulated value is returned.
GitHub: plone/volto
46 47 48 49 50 51 52 53 54 55
* Get messages from separate JSON files * @function getMessages * @return {Object} Object with messages */ function getMessages() { return reduce( concat( {}, ...map( // We ignore the existing customized shadowed components ones, since most
315 316 317 318 319 320 321 322 323 324
module.exports.range = _.range; module.exports.rangeRight = _.rangeRight; module.exports.rcurry2 = _.rcurry2; module.exports.rcurry3 = _.rcurry3; module.exports.rearg = _.rearg; module.exports.reduce = _.reduce; module.exports.reduceRight = _.reduceRight; module.exports.reductions = _.reductions; module.exports.reject = _.reject; module.exports.remove = _.remove;
+ 92 other calls in file
Ai Example
1 2 3 4 5 6 7 8 9 10
const _ = require("lodash"); const numbers = [1, 2, 3, 4, 5]; const sum = _.reduce( numbers, (accumulator, current) => accumulator + current, 0 ); console.log(sum); // Output: 15
In this example, _.reduce() is called with the array numbers as the first argument, a function that adds the current element to the accumulated value as the second argument, and 0 as the third argument, which specifies that the initial value of the accumulator should be 0. The resulting sum of all elements in the array is stored in the sum variable, which is then printed to the console.
GitHub: adogor/npm-autolink
![adogor profile picture](/adogor.png?size=40)
58 59 60 61 62 63 64 65 66 67
dependencyTree, (res, projectConf, projectName) => { const linkList = fileContent.link[projectName]; if (linkList && projectConf.dependencies) { // If we have a linkList for this project && it has dependencies const toLinkInProject = _.reduce( projectConf.dependencies, (res2, depConf, depName) => { fileContent.link; if (linkList.includes(depName)) {
+ 11 other calls in file
310 311 312 313 314 315 316 317 318 319 320
var Type = parseableResourceTypes[resource.sys.type]; return Type.parse(resource); } function stringifyArrayValues(object) { return _.reduce(object, function(object, value, key) { object[key] = _.isArray(value) ? value.join(',') : value; return object; }, {}); }
+ 530 other calls in file
GitHub: mdmarufsarker/lodash
254 255 256 257 258 259 260 261 262 263 264 265 266
console.log(orderBy); // => ['c', 'a', 'b'] const partition = _.partition([1, 2, 3], n => n % 2); console.log(partition); // => [[1, 3], [2]] const reduce = _.reduce([1, 2], (sum, n) => sum + n, 0); console.log(reduce); // => 3 const reduceRight = _.reduceRight([1, 2], (sum, n) => sum + n, 0); console.log(reduceRight); // => 3
+ 15 other calls in file
262 263 264 265 266 267 268 269 270 271
} acc[el.name] = [el]; return acc; }, {}); return _.reduce(fieldTypes, (acc, el, index) => { const fieldLanguage = _.find(fieldsLanguages, (l) => l.type === index); const existedLanguages = _.get(fieldLanguage, 'languages', []); const nativeLang = _.filter(
+ 17 other calls in file
513 514 515 516 517 518 519 520 521 522
}, 'status.title': { $nin: REMOVE_OBJ_STATUSES }, }, }); const options = _.reduce(wobjects, (acc, el) => { el.fields = addDataToFields({ isOwnershipObj: !!ownership.length, fields: _.compact(el.fields), filter,
+ 5 other calls in file
97 98 99 100 101 102 103 104 105
const pathParamMatches = (routeName || "").match( /({(([a-zA-Z]-?_?\.?){1,})([0-9]{1,})?})|(:(([a-zA-Z]-?_?\.?){1,})([0-9]{1,})?:?)/g, ); // used in case when path parameters is not declared in requestInfo.parameters ("in": "path") const pathParams = _.reduce( pathParamMatches, (pathParams, match) => { const paramName = _.replace(match, /\{|\}|\:/g, "");
+ 7 other calls in file
GitHub: sergeyksv/tinelic
35 36 37 38 39 40 41 42 43 44 45
}); this.name = 'ValidationError'; this.message = es; this.subject = 'Invalid Data'; this.data = _.reduce(invalid.errors, function (m, f) { m.push(_.pick(f, ['property', 'message'])); return m; },[]); };
744 745 746 747 748 749 750 751 752
return nodes } self.totalpending = function(){ return _.reduce(self.initednodes(), function(r, node){ return r + node.statistic.pending() }, 0) }
+ 7 other calls in file
887 888 889 890 891 892 893 894 895 896
var field_names = {}; _.each(model.fields, function(field){ field_names[field.name] = 1; }); for(var display_layout_name in model.display_layouts){ var display_layout = model.display_layouts[display_layout_name]; var column_names = {}; display_layout.columns = _.reduce(display_layout['columns'],function(rslt,column){ if(_.isString(column)){ let column_name = column; if(!(column_name in field_names)){ _this.LogInit_ERROR('Display layout column not found: '+model.id+'::'+display_layout_name+'::'+column_name); return rslt; } if(column_name in column_names){ _this.LogInit_ERROR('Duplicate display layout column: '+model.id+'::'+display_layout_name+'::'+column_name); return rslt; }
GitHub: sluukkonen/iiris
184 185 186 187 188 189 190 191 192 193
const lodashCallback = (a, b) => a + b const ramdaCallback = (a, b) => a + b const nativeCallback = (a, b) => a + b return { iiris: () => A.reduce(iirisCallback, 0, array), lodash: () => _.reduce(array, lodashCallback, 0), ramda: () => R.reduce(ramdaCallback, 0, array), native: () => array.reduce(nativeCallback, 0), } },
GitHub: inPact/utils
![inPact profile picture](/inPact.png?size=40)
21 22 23 24 25 26 27 28 29 30
* Projects the values of each key in object by running them through projector. * @param object - the object whose values to project * @param valueProjector - a function that receives a value and returns the projected result. */ mapObject(object, valueProjector) { return _.reduce(object, (res, val, key) => { res[key] = valueProjector(val, key, object); return res }, {}); },
+ 31 other calls in file
GitHub: nasolodar/test
507 508 509 510 511 512 513 514 515 516
* @return {Model[]} Parsed model list possibly containing additional pivot models. */ parsePivot(models) { return _.map(models, (model) => { // Separate pivot attributes. const grouped = _.reduce( model.attributes, (acc, value, key) => { if (hasPivotPrefix(key)) { acc.pivot[removePivotPrefix(key)] = value;
GitHub: norjs/cloud-backend
17 18 19 20 21 22 23 24 25 26 27
console.log("#4 req=", req, " res=", res); return "hello"; } ]; var func = _.reduce( funcs, (a, b) => (req, res, next) => a(req, res, err => { if(err !== undefined) throw err; return b(req, res, next);
117 118 119 120 121 122 123 124 125 126
permission: Models.Permission, setting: Models.Settings }; // Iterate through the object types, i.e. ['post', 'tag', 'user'] return _.reduce(objTypes, function (objTypeHandlers, objType) { // Grab the TargetModel through the objectTypeModelMap var TargetModel = objectTypeModelMap[objType]; // Create the 'handler' for the object type;
GitHub: web-tiny/utils
65 66 67 68 69 70 71 72 73 74 75
} return a; } function lameCSV (str) { return _.reduce(str.split('\n'), (table, row) => { table.push(_.map(row.split(','), c => c.trim())); return table; }, []) }
54 55 56 57 58 59 60 61 62 63
.all([ queryFunction('SELECT name_eng, name_kor FROM user'), queryFunction('SELECT paper_doms_conf.id, paper_status.name_eng as paper_name_eng, paper_status.name_kor as paper_name_kor, paper_conf_presentation.name_eng, paper_conf_presentation.name_kor, project.subject, research.title as research_title, conf_city, conf_startdate, conf_enddate, conf_name, author1, author2, author3, author4, author5, author6, author7, author8, paper_doms_conf.title, year, month, volumn, startpage, endpage, paper_file, coverpage_file, listpage_file, firstpage_file FROM paper_doms_conf LEFT JOIN paper_status ON paper_doms_conf.statusid = paper_status.id LEFT JOIN paper_conf_presentation ON paper_doms_conf.presentationid = paper_conf_presentation.id LEFT JOIN project ON paper_doms_conf.projectid = project.id LEFT JOIN research ON paper_doms_conf.researchid = research.id'), ]) .then(([member_rows, rows]) => { const name_map = _.reduce(member_rows, (result, row) => { return _.defaults(result, { [row.name_kor]: row.name_eng }); }, {}); var dateArr = [];
+ 17 other calls in file
lodash.get is the most popular function in lodash (7670 examples)