Process a Dictionary and Return Each Entry in React

How to map a dictionary in reactJS?

"Dictionaries" in Javascript are called objects and you can iterate over them in a very similar way to arrays.

var dict = this.props.dict;

for (var key in dict) {
  // Do stuff. ex: console.log(dict[key])
}

If you were thinking of using map so that at the end of the iteration you had a complete array, then inside your for..in loop you could push to an array you declare earlier.

var dict = this.props.dict;
var arr = [];

for (var key in dict) {
  arr.push(dict[key]);
}

how to loop through a nested dictionary or json data in Reactjs

Of course that I cant make an entire project solution for you but the function that you wanted must have this kind of logic.

const jsonData = [{  "squadName": "Super hero squad",  "homeTown": "Metro City",  "formed": 2016,  "secretBase": "Super tower",  "active": true,  "members": [    {      "name": "Molecule Man",      "age": 29,      "secretIdentity": "Dan Jukes",      "powers": [        "Radiation resistance",        "Turning tiny",        "Radiation blast"      ]    },    {      "authorization": "Black card",      "location": [        "Next",        "Previous",        "Here"      ]    }  ]}]
jsonData.forEach(item=>{    item.members.map((member)=>{        if(member.location&&member.location[0]){        //Do whatever, maybe you want to use return statement in there      console.log(member.location)    }    else{          //do something else, or add more conditions      console.log("There's no location in it")    }  })})

How Do I push multiple marker a dictionary in react-native on ios map

solve it. thanks kappa!

fetch('http://www.mywebsite.search.php')
  .then((response) => response.json())
  .then((responseData) => {
    console.log('Fetch Success');
    console.log(responseData);

    var tempMarker = [];
    for (var p in responseData) {
      tempMarker.push({
        latitude: responseData[p]['lat'],
        longitude: responseData[p]['lng'],
      });
    }

    this.setState({
      marker: tempMarker,
    });
  })
  .catch((error) => {
    console.warn(error);
  })
  .done();

How to access an object inside another object in a map in react

As stated in the comments,

The problem is that one or more elements in your array doesn't have the .price.price property which would cause a type error since it doesn't exist.

To fix this you could do item?.price?.price

The optional chaining operator (?.) enables you to read the value of a property located deep within a chain of connected objects without having to check that each reference in the chain is valid.

see more: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining

Array in a Redux State, React

try this:

state:

const initialState = {
  productinuse: []
}

reducer:

const productinuse = (state = initialState, action) => {
  switch (action.type) {
    case 'productinuse':
      return Object.assign({}, state, {
        productinuse: [...state.productinuse, action.payload],
      });
    default:
      return state;
  }
};
export default productinuse;

How to return only 3 elements from arrays of object in React

Using Array.slice will limit the array to only include the first x elements. If there is less than x elements in the array it will simply leave the array as-is:

{
  users.slice(0, 3).map(
    <UserItem key={user.id} user={user} />
  ))
}

Another issue you may be running into is not using the user data from the state:

{
  this.state.users.slice(0, 3).map(
    <UserItem key={user.id} user={user} />
  ))
}

You can read more about React state here.

Edit: As pointed out by @ChristopherNgo Array.slice is non-inclusive so it should be 0 to 3 for 3 elements.