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JavaScript: parseFloat() function

Description

The parseFloat is used to get a floating value from a string. parseFloat is a top-level function and is not associated with any object.

Syntax

parseFloat(string)

Parameters

string: Required. A string that represents the value to test.

Example of parseFloat() function

The following example demonstrate how to use parseFloat() function.

JavaScript Code:

console.log('"21" -> '+parseFloat("21"));
console.log('"21.42" -> '+parseFloat("21.42"));
console.log('"100 234 54" -> '+parseFloat("100 234 54"));
console.log('"89 Math" ->'+parseFloat("89 Math"));
console.log('"Math 89" ->'+parseFloat("Math 89"));

View the example in the browser

Live demo:

See the Pen parsefloat-function-1 by w3resource (@w3resource) on CodePen.


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Next: JavaScript: NaN



JavaScript: Tips of the Day

semicolon (;)

function nums(a, b) {
  if (a > b) console.log('a is bigger');
  else console.log('b is bigger');
  return;
  a + b;
}

console.log(nums(4, 2));
console.log(nums(1, 2));

In JavaScript, we don't have to write the semicolon (;) explicitly, however the JavaScript engine still adds them after statements. This is called Automatic Semicolon Insertion. A statement can for example be variables, or keywords like throw, return, break, etc.
Here, we wrote a return statement, and another value a + b on a new line. However, since it's a new line, the engine doesn't know that it's actually the value that we wanted to return. Instead, it automatically added a semicolon after return. You could see this as:

return;
a + b;
This means that a + b is never reached, since a function stops running after the return keyword. If no value gets returned, like here, the function returns undefined. Note that there is no automatic insertion after if/else statements!

Ref: https://bit.ly/3jFRBje