Loop through array and return value that is matched

Question

I would like to find a solution that returns the following result when any of the property "value" is true.

This is what I have tried so far, but so far it has not worked

public displayCondition(data:any){
const items = data.status.map((status: { value: boolean; }) =>{
  staus.value === true;
})
return items;

}

Input

const data: [
      {
        name: "php",
        status: [
          {
            value: "true"
          },
          {
            value: "false"
          }
        ]
      },
      {
        name: "java",
        status: [
          {
            value: "false"
          },
          {
            value: "false"
          }
        ]
      }
    ]

Output

[
  {
    name: "php",
    status: [
      {
        value: "true"
      },
      {
        value: "false"
      }
    ]
  }
]

Your code also has a syntax error (staus.value). Please always post the actual code. — jarmod
– jarmod, Commented Jul 26, 2022 at 15:30

ggorlen · Accepted Answer · 2022-07-26 15:37:16Z

Your data structure has an antipattern: using strings "true" and "false" as booleans true and false. I suggest converting it to real booleans unless you have a very compelling reason to do otherwise. It should be possible to say if (data[0].status[0]) {...} but that's an always-true condition when you use strings.

In your original code, the condition staus.value === true; is always false as it compares a string with a boolean.

Here's how to make the conversion:

const data = [
  {
    name: "php",
    status: [
      {value: "true"},
      {value: "false"}
    ]
  },
  {
    name: "java",
    status: [
      {value: "false"},
      {value: "false"}
    ]
  }
];

data.forEach(e => e.status.forEach(e => {
  e.value = e.value === "true";
}));
console.log(data);

Back to the main problem. map isn't used to search an array; it's used to apply a transformation on each entry in an array.

Try .filter (return all elements matching a predicate) and .some (return true if the predicate is true for any item in an array, otherwise false):

const data = [
  {
    name: "php",
    status: [
      {value: "true"},
      {value: "false"}
    ]
  },
  {
    name: "java",
    status: [
      {value: "false"},
      {value: "false"}
    ]
  }
];

const result = data.filter(e => e.status.some(e => e.value === "true"));
console.log(result);

// or if you made the boolean conversion:
//const result = data.filter(e => e.status.some(e => e.value));

Use .find rather than .filter if you want only the first item that matches the predicate (or null if none matched).

PeterKA · Accepted Answer · 2022-07-28 01:09:56Z

0

You can use the Array#filter and Array#some methods and object destructuring as follows:

const data = [ { name: "php", status: [ { value: "true" }, { value: "false" } ] }, { name: "java", status: [ { value: "false" }, { value: "false" } ] } ],

      output = data.filter(
          ({status}) => status.some(
              ({value}) => value === "true"
          )
      );
      
console.log( output );

answered Jul 28, 2022 at 1:09

PeterKA

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