CODEWITHSUNDEEP
javascriptreactjsreduxreact-redux
ganesh kaspate
ganesh kaspate

Reputation: 2685

How to replace a value of a key in a object

Him I am new to the react redux. I have an array of objects which is like,

let result = [ {Id :'a',temp:5,data:'abc (c:1'},{Id :'a',temp:5,data:'pqr (c:1'}{Id :'a',temp:5,data:'xyz (c:1'}]

Now, what I want to do is that there is key called data with some value, I want to take the value which is before that bracket only in that data key.

what I want to look an object ,

{Id :'a',count:5,data:'abc'}

what I have is , I have an regex which I use to get that value,

and I have used for loop ,

for (let i = 0; i <= result.length - 1; i++) {
         let regex = /^[^\(]+/;
         let value = data.match(regex)[0].trim();
        result[i].data = value 
      }


fetchQuestions() {
    let previous_data = { ...this.props.data  };
    let result = [];
    for (let key in previous_data) {
      result = [...result, ...previous_data[key]];
    }
    for (let i = 0; i <= result.length - 1; i++) {
      let regex = /^(.*)\(/;
      let value = result[i].technology.match(regex)[1].trim();
      result[i].technology = value;
    }
    this.props.fetchQuestions(result);
  }

In this this.props.data is the reducer data .Now what I want to do was, I have to get some data from this and do some manipulation. but here, it is directly updating my reducer values itself, But I have used spread operator to get the copy of that data ,but still its updating the reducers values.

But I am not getting the value which I expect. Can any one help me with this ?

Upvotes: 0

Views: 95

Answers (5)

Shubham Khatri
Shubham Khatri

Reputation: 281656

You can write a regex that creates a group for the value before ( and then get it from the match

let result= [
  {
    Id: 'a',
    temp: 5,
    data: 'abc (c:1'
  },
  {
    Id: 'a',
    temp: 5,
    data: 'pqr (c:1'
  },
  {
    Id: 'a',
    temp: 5,
    data: 'xyz (c:1'
  }
]
for (let i = 0; i <= result.length - 1; i++) {
         let regex = /^(.*)\(/;
         let value = result[i].data.match(regex)[1].trim();
        result[i].data = value 
    }
    
console.log(result);

Upvotes: 1

Brandon
Brandon

Reputation: 9

let result = [ {Id :'a',temp:5,data:'abc (c:1'},{Id :'a',temp:5,data:'pqr (c:1'},{Id :'a',temp:5,data:'xyz (c:1'}]

const new_result = result.map((item) => {
    let regex = /^[^\(]+/;
  let value = item.data.match(regex)[0].trim();
  item.data = value;
  return item;
});

console.log(new_result);

Upvotes: 0

Kol007
Kol007

Reputation: 292

Try this one.

  result.map(el => {
        el.data = el.data.match(/^(\w+)/)[0];
        return el;
    })

Upvotes: 0

CertainPerformance
CertainPerformance

Reputation: 370689

You need to access the data property of each object while you're iterating, in order to use a .match on it:

let result = [{
  Id: 'a',
  temp: 5,
  data: 'abc (c:1'
}, {
  Id: 'a',
  temp: 5,
  data: 'pqr (c:1'
}, {
  Id: 'a',
  temp: 5,
  data: 'xyz (c:1'
}];
for (let i = 0; i <= result.length - 1; i++) {
  const { data } = result[i];
  let regex = /^[^\(]+/;
  let value = data.match(regex)[0].trim();
  result[i].data = value;
}
console.log(result);

But, seeing as you're using react, you might consider using .map instead, which won't mutate the original objects:

let result = [{
  Id: 'a',
  temp: 5,
  data: 'abc (c:1'
}, {
  Id: 'a',
  temp: 5,
  data: 'pqr (c:1'
}, {
  Id: 'a',
  temp: 5,
  data: 'xyz (c:1'
}];
console.log(
  result.map(({ data, ...rest }) => ({
    data: data.match(/^[^(]+[^( ]/)[0],
    ...rest
  }))
);

Note that if you make the final matched character in the regex [^( ] (match anything but a ( or a space), there's no need for trim anymore.

Upvotes: 1

Ankit Agarwal
Ankit Agarwal

Reputation: 30739

You can use split('(') instead of regex to get the same output:

let result = [{
  Id: 'a',
  temp: 5,
  data: 'abc (c:1'
}, {
  Id: 'a',
  temp: 5,
  data: 'pqr (c:1'
}, {
  Id: 'a',
  temp: 5,
  data: 'xyz (c:1'
}];
for (let i = 0; i <= result.length - 1; i++) {
  let value = result[i].data.split('(')[0].trim();
  result[i].data = value
}
console.log(result);

Upvotes: 0

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