Convert string to number in JavaScript; Through this tutorial, i am going to share with you how to convert string to number or decimal number in javaScript.
JavaScript Convert String to Number
Use the following 3 different ways or methods to convert string to number or 2,3,4, etc, decimal places in javascript; as shown below:
- Convert string to int in javascript with parseInt()
- Convert string to int in javascript with parseFloat()
- Convert string to int in javascript with number()
Convert string to int in javascript with parseint
Using the javascript parseInt() method to convert the string to a number.
Syntax of parseInt() function
parseInt(string, radix)
Example 1 – Convert string to integer in javascript using parseInt
Here, i will take this simple example of convert string to number in JavaScript using parseInt() function; as shown below:
// returns a Integer no a = parseInt("20"); document.write('parseInt("20") = ' + a + "<br>"); // Not a Number character b = parseInt("30.00"); document.write('parseInt("30.00") = ' + b + "<br>"); // returns NaN on Non numeral character c = parseInt("2.366"); document.write('parseInt("2.366") = ' + c + "<br>"); // returns Integer value of a Floating point Number d = parseInt("3.14"); document.write('parseInt("3.14") = ' + d + "<br>"); // only first Number it encounters e = parseInt("22 3 2019"); document.write('parseInt("22 3 2019") = ' + e + "<br>");
Output of the above code is:-
parseInt("20") = 20 parseInt("30.00") = 30 parseInt("2.366") = 2 parseInt("3.14") = 3 parseInt("22 3 2019") = 22
Convert string to int in javascript with parseFloat()
Using javascript parseFloat() method to convert the string into a floating number or 2 , 3 etc decimal places.
Syntax of javaScript parseFloat() method
parseFloat(string)
Example 1 – Convert string to int in javascript with parseFloat()
Here, i will take example for convert string to number with 2,3, 4,etc decimal places in aJavaScript using parseFloat() method; as shown below:
// return float value a = parseFloat(" 10 ") document.write('parseFloat(" 10 ") = ' +a +"<br>"); b = parseFloat("123abc") document.write('parseFloat("123abc") = '+b +"<br>"); // returns NaN value c = parseFloat("abc456") document.write('parseFloat("abc456") = ' +c +"<br>"); d = parseFloat("3.14") document.write('parseFloat("3.14") = '+d +"<br>"); // returns only first Number e = parseFloat("18 2 2019") document.write('parseFloat("18 2 2019") = ' +e +"<br>");
Output of the above code is:
parseFloat(" 10 ") = 10
parseFloat("123abc") = 123
parseFloat("abc456") = NaN
parseFloat("3.14") = 3.14
parseFloat("18 2 2019") = 18
Convert string to int in javascript with number()
Using javascript number() method to convert the string into number in javascript.
Syntax of JS number() method
Number(string)
Example 1 – Convert string to int in javascript with number()
Here, i will take an example for convert string to integer in javascript using number() method; as shown below:
// return float value a = Number(" 10 ") document.write('Number(" 10 ") = ' +a +"<br>"); b = Number("125.3") document.write('Number("125.3") = '+b +"<br>"); // returns NaN value c = Number("abc456") document.write('Number("abc456") = ' +c +"<br>"); d = Number("42px") document.write('Number("42px") = '+d +"<br>");
Output of the above code is:
Number(” 10 “) = 10
Number(“125.3”) = 125.3
Number(“abc456”) = NaN
Number(“42px”) = NaN