How can I convert a string to a boolean in TypeScript for an Angular 4 application?

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1

How can I convert a string to a boolean in TypeScript for an Angular 4 application?

I am working with local storage to store and retrieve boolean values as strings. Here’s how I’m doing it:

In app.component.ts: localStorage.setItem('CheckOutPageReload', this.btnLoginNumOne + ',' + this.btnLoginEdit);

Here, this.btnLoginNumOne and this.btnLoginEdit are string values, either “true” or “false”.

In mirror.component.ts, I retrieve and process these values:

if (localStorage.getItem('CheckOutPageReload')) {
    let stringToSplit = localStorage.getItem('CheckOutPageReload');
    this.pageLoadParams = stringToSplit.split(',');

    this.btnLoginNumOne = this.pageLoadParams[0]; // Error: boolean value is not assignable to string
    this.btnLoginEdit = this.pageLoadParams[1]; // Error: boolean value is not assignable to string
}

In this component, this.btnLoginNumOne and this.btnLoginEdit are expected to be boolean values.

I have tried various solutions, but none have worked. How can I correctly convert the string values from local storage to boolean values in TypeScript? Please provide guidance on how to handle this conversion using the keyword typescript string to boolean.

2

Hi Neha,

Method 1: Using Regular Expressions

var stringValue = "true";
var boolValue = (/true/i).test(stringValue); // returns true

Method 2: Simple Comparison

var stringValue = "true";
var boolValue = (stringValue == "true");   // returns true

Method 3: Using JSON.parse

var stringValue = "true";
var boolValue = JSON.parse(stringValue);   // returns true

Method 4: Case-Insensitive Comparison

var stringValue = "true";
var boolValue = stringValue.toLowerCase() == 'true'; // returns true

Method 5: Using a Custom Function

var stringValue = "true";
var boolValue = getBoolean(stringValue); // returns true

function getBoolean(value) {
   switch(value) {
        case true:
        case "true":
        case 1:
        case "1":
        case "on":
        case "yes":
            return true;
        default:
            return false;
    }
}