This tutorial will show you how to convert a string into a JavaScript boolean. You might have a string that is “true” or something like that. To make the java script string a boolean value, you need to make sure that it’s either 0 or true.
Casting to boolean can be done in many different ways. JavaScript may use vanilla js, or other libraries to perform true and false conversions. Let’s look at some examples.
Example 1:
stringToBoolean: function(string){
switch(string.toLowerCase().trim()){
case "true": case "yes": case "1": return true;
case "false": case "no": case "0": case null: return false;
default: return Boolean(string);
}
}
Example 2:
if (String(a).toLowerCase() == “true”) …
It’s true:
String(true) == "true" //returns true
String(false) == "true" //returns false
String("true") == "true" //returns true
String("false") == "true" //returns false
Example 3:
var parseBool = function(str)
{
// console.log(typeof str);
// strict: JSON.parse(str)
if(str == null)
return false;
if (typeof str === 'boolean')
{
return (str === true);
}
if(typeof str === 'string')
{
if(str == "")
return false;
str = str.replace(/^\s+|\s+$/g, '');
if(str.toLowerCase() == 'true' || str.toLowerCase() == 'yes')
return true;
str = str.replace(/,/g, '.');
str = str.replace(/^\s*\-\s*/g, '-');
}
// var isNum = string.match(/^[0-9]+$/) != null;
// var isNum = /^\d+$/.test(str);
if(!isNaN(str))
return (parseFloat(str) != 0);
return false;
}
These resources might be of interest:
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