How can I substitute a specific portion of a string with values that correspond to items in an object array?

Question

How can I substitute a specific portion of a string with values that correspond to items in an object array?

I am currently working on a task that involves extracting values from objects in a string to perform mathematical operations. While I have managed to retrieve the data and match the values enclosed in brackets, I am facing a roadblock in terms of what steps to take next or whether there might be a more efficient approach to accomplish this. Here is a sample of the scenario I am dealing with:

var array = [{name: M, value: 45},{name: F, value: 23},{name: L, value: 9}]
var string = '( 2 * [M] ) * ( 5 / [F] ) * ( 100 + [L] )'

In essence, I am seeking a solution where I can substitute the value of "M" for "[M]", the value of "F" for "[F]", and so forth within the string formula.

javascript arrays string

Answer 1

Answer №1

If you're looking to work with formulas and calculations, give nerdamer a try. It's a great tool for handling mathematical expressions.

let variables = {M: 45, F: 23, L: 9};
let equation = '( 2 * M ) * ( 5 / F ) * ( 100 + L )';

console.log(
  equation,
  '=',
  nerdamer(
    equation,
    variables
  )
  .evaluate()
  .text()
);

<script src="https://cdn.jsdelivr.net/npm/nerdamer@latest/nerdamer.core.js"></script>

For a simpler approach, you can use the following method:

let variables = {M: 45, F: 23, L: 9};
let equation = '( 2 * [M] ) * ( 5 / [F] ) * ( 100 + [L] )';

function calculate(equation, variables)
{
  let newEquation = equation.replaceAll(/\[[A-Z]\]/gi, function(v)
  {
    return variables[v[1]];
  });
  
  return eval(newEquation);
}

console.log(calculate(equation, variables));

Answer 2

If you're looking to work with formulas and calculations, give nerdamer a try. It's a great tool for handling mathematical expressions.

let variables = {M: 45, F: 23, L: 9};
let equation = '( 2 * M ) * ( 5 / F ) * ( 100 + L )';

console.log(
  equation,
  '=',
  nerdamer(
    equation,
    variables
  )
  .evaluate()
  .text()
);

<script src="https://cdn.jsdelivr.net/npm/nerdamer@latest/nerdamer.core.js"></script>

For a simpler approach, you can use the following method:

let variables = {M: 45, F: 23, L: 9};
let equation = '( 2 * [M] ) * ( 5 / [F] ) * ( 100 + [L] )';

function calculate(equation, variables)
{
  let newEquation = equation.replaceAll(/\[[A-Z]\]/gi, function(v)
  {
    return variables[v[1]];
  });
  
  return eval(newEquation);
}

console.log(calculate(equation, variables));

Answer 3

Answer №2

Check out this neat one-line solution:

const arr = [{name: 'M', value: 45},{name: 'F', value: 23},{name: 'L', value: 9}]
const str = "( 2 * [M] ) * ( 5 / [F] ) * ( 100 + [L] )";

const doCalculation = (arr) => arr.reduce((acc, val)=>{ return acc.replace(`[${val.name}]`, val.value)}, str);

console.log('Final Result: ', eval(doCalculation(arr)));

Answer 4

Check out this neat one-line solution:

const arr = [{name: 'M', value: 45},{name: 'F', value: 23},{name: 'L', value: 9}]
const str = "( 2 * [M] ) * ( 5 / [F] ) * ( 100 + [L] )";

const doCalculation = (arr) => arr.reduce((acc, val)=>{ return acc.replace(`[${val.name}]`, val.value)}, str);

console.log('Final Result: ', eval(doCalculation(arr)));

Answer 5

Answer №3

Here is a helpful code snippet for you to explore. Enjoy!

let values = [{item: "X", quantity: 30}, {item: "Y", quantity: 12}, {item: "Z", quantity: 5}];
let formula = '( 3 * [X] ) * ( 10 / [Y] ) * ( 50 + [Z] )';

const calculateValue = (array, equationWithVars) => {
  let result = equationWithVars;
  
  array.forEach(element => {
    result = result.replaceAll(`[${element.item}]`, element.quantity);
  })
  
  return result;
}

console.log(calculateValue(values, formula));

Answer 6

Here is a helpful code snippet for you to explore. Enjoy!

let values = [{item: "X", quantity: 30}, {item: "Y", quantity: 12}, {item: "Z", quantity: 5}];
let formula = '( 3 * [X] ) * ( 10 / [Y] ) * ( 50 + [Z] )';

const calculateValue = (array, equationWithVars) => {
  let result = equationWithVars;
  
  array.forEach(element => {
    result = result.replaceAll(`[${element.item}]`, element.quantity);
  })
  
  return result;
}

console.log(calculateValue(values, formula));

How can I substitute a specific portion of a string with values that correspond to items in an object array?

Answer №1

Answer №2

Answer №3

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