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- # undefsafe
-
- Simple *function* for retrieving deep object properties without getting "Cannot read property 'X' of undefined"
-
- Can also be used to safely set deep values.
-
- ## Usage
-
- ```js
- var object = {
- a: {
- b: {
- c: 1,
- d: [1,2,3],
- e: 'remy'
- }
- }
- };
-
- console.log(undefsafe(object, 'a.b.e')); // "remy"
- console.log(undefsafe(object, 'a.b.not.found')); // undefined
- ```
-
- Demo: [https://jsbin.com/eroqame/3/edit?js,console](https://jsbin.com/eroqame/3/edit?js,console)
-
- ## Setting
-
- ```js
- var object = {
- a: {
- b: [1,2,3]
- }
- };
-
- // modified object
- var res = undefsafe(object, 'a.b.0', 10);
-
- console.log(object); // { a: { b: [10, 2, 3] } }
- console.log(res); // 1 - previous value
- ```
-
- ## Star rules in paths
-
- As of 1.2.0, `undefsafe` supports a `*` in the path if you want to search all of the properties (or array elements) for a particular element.
-
- The function will only return a single result, either the 3rd argument validation value, or the first positive match. For example, the following github data:
-
- ```js
- const githubData = {
- commits: [{
- modified: [
- "one",
- "two"
- ]
- }, /* ... */ ]
- };
-
- // first modified file found in the first commit
- console.log(undefsafe(githubData, 'commits.*.modified.0'));
-
- // returns `two` or undefined if not found
- console.log(undefsafe(githubData, 'commits.*.modified.*', 'two'));
- ```
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