How to use the isUndefined function from underscore

Find comprehensive JavaScript underscore.isUndefined code examples handpicked from public code repositorys.

underscore.isUndefined is a function provided by the Underscore.js library that determines if a given value is undefined.

validator.js

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}


function AvroArray(itemSchema) {


  function validateArgs(itemSchema) {
    if (_.isNull(itemSchema) || _.isUndefined(itemSchema)) {
      throw new InvalidSchemaError('Array "items" schema should not be null or undefined');
    }
  }

+ 3 other calls in file

index.js

GitHub: Tolar-HashNET/web3js

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var Common = require("ethereumjs-common").default;
const elliptic = require("elliptic");
const secp256k1 = new elliptic.ec("secp256k1"); // eslint-disable-line


var isNot = function (value) {
    return _.isUndefined(value) || _.isNull(value);
};
let fromPrivateFn = Account.fromPrivate;
let recoverFn = Account.recover;
var Accounts = function Accounts() {

+ 3 other calls in file

How does underscore.isUndefined work?

underscore.isUndefined is a function provided by the Underscore.js library that determines if a given value is undefined. When called, underscore.isUndefined takes a single argument, which is the value to be tested. It then checks if the value is undefined using the typeof operator and returns a boolean value indicating whether or not the value is undefined. In JavaScript, the value undefined represents a variable that has been declared but has not been assigned a value. When a function does not return a value, the default return value is also undefined. By using underscore.isUndefined, you can easily check whether a given value is undefined in your Underscore.js code. Overall, underscore.isUndefined provides a convenient way to test whether a given value is undefined, allowing you to write more robust and error-free code.

markdown.js

GitHub: cloakscn/yapi-docker

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}
let tpl = ``;
Object.keys(text || {}).map((item, index) => {
  let name = messageMap[item];
  let value = text[item];
  tpl += _.isUndefined(text[item])
    ? ''
    : `<p key=${index}><span style="font-weight: '700'">${name}: </span><span>${value.toString()}</span></p>`;
});

+ 2 other calls in file

interface.js

GitHub: cloakscn/yapi-docker

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async schema2json(ctx) {
  let schema = ctx.request.body.schema;
  let required = ctx.request.body.required;

  let res = yapi.commons.schemaToJson(schema, {
    alwaysFakeOptionals: _.isUndefined(required) ? true : required
  });
  // console.log('res',res)
  return (ctx.body = res);
}

+ 3 other calls in file

Ai Example

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const _ = require("underscore");

const x = undefined;
const y = "Hello, world!";

console.log(_.isUndefined(x)); // true
console.log(_.isUndefined(y)); // false

In this example, we use underscore.isUndefined to check whether two values are undefined. We first import the Underscore.js library using the require function and assign it to the variable _. We then create two variables x and y. x is explicitly set to undefined, while y is set to a string value. We call _.isUndefined twice, passing in x and y as the arguments. This checks whether each value is undefined and returns a boolean value indicating whether or not it is. Finally, we log the results of both calls to _.isUndefined to the console, which in this case will be true for x and false for y. Note that in order to use underscore.isUndefined, you need to have the Underscore.js library installed and imported in your application.

base.recordFieldAudit.trigger.js

GitHub: 444748104/oa

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    }
  };


const transformFieldValue = async function(field, value, options) {
    var selected_value, space_id, utcOffset;
    if (_.isNull(value) || _.isUndefined(value)) {
      return;
    }
    utcOffset = options.utcOffset;
    space_id = options.space_id;

markdown.js

GitHub: evan-org/yapi

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function tableCol(col, columns, level) {
  let tpl = "";
  columns.map((item, index) => {
    let dataIndex = item.dataIndex;
    let value = col[dataIndex];
    value = _.isUndefined(value) ? "" : value;
    let text = "";


    switch (dataIndex) {
      case "sub":

+ 11 other calls in file

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