Javascript 如何在react中更新状态，以便使用array.map函数更新数组中对象的值

函数handleFeetAndInch使用index更新状态，同时使用array.map并传递更新状态的函数，但所有调用的函数都会引用映射的状态，因此其他映射索引不会获取更新的状态值，根据测量对象具有以下属性的情况，是否有这种或其他方法转换值的实践： 状态={measurements:[{name:''，value:''，algo:''}…]

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您没有正确使用映射函数。返回一个新数组，原始数组的值映射到新值

Update

handleFeeAndInch

只是作为映射回调，将新值返回到新数组中，然后设置该数组的状态

handleFeetandInch = (key, nameValue, value) => {
  let realFeet = (value * 0.3937) / 12;
  let feet = Math.floor(realFeet);
  let inches = Math.round((realFeet - feet) * 12);
  let updatedValue = `${feet}'${inches}"`;
  const newMeasurement = [...this.state.measurements];
  newMeasurement[key] = {
    name: nameValue,
    value: updatedValue
  };
  this.setState({
    measurements: newMeasurement
  });
};

handleUnitChange = () => {
  if (this.state.isCm) {
    // reset State
  } else {
    this.state.measurements.map((measurement, key) =>
      measurement.algo === 1
        ? this.handleFeetandInch(key, measurement.name, measurement.value)
        : this.handleInches(key, measurement.name, measurement.value)
    );
    this.setState(prevState => ({
      isCm: !prevState.isCm
    }));
  }
};

handleFeetandInch = (key, nameValue, value) => {
  let realFeet = (value * 0.3937) / 12;
  let feet = Math.floor(realFeet);
  let inches = Math.round((realFeet - feet) * 12);
  let updatedValue = `${feet}'${inches}"`;

  // return new measurement value
  return {
    name: nameValue,
    value: updatedValue
  };
};

handleUnitChange = () => {
  if (this.state.isCm) {
    // reset State
  } else {
    // get array of new measurements
    const newMeasurements = this.state.measurements.map((measurement, key) =>
      measurement.algo === 1
        ? this.handleFeetandInch(key, measurement.name, measurement.value)
        : this.handleInches(key, measurement.name, measurement.value)
    );
    this.setState(prevState => ({
      measurements: newMeasurements
    }));
    this.setState(prevState => ({
      isCm: !prevState.isCm
    }));
  }
};