Since you want a primitive number rather than a Number wrapper object, make sure you don't put new in front of the Number function. It's more strict: if it doesn't understand the whole of the string than it returns NaN, so you can't use it for strings like 97px. This has different behavior to the parse methods (although it still ignores whitespace). I prefer to do this explicitly, var cast = Number("97") parseInt understands radixes up to base 36, in which case both upper and lower case letters are treated as equivalent.Ĭhanging the Type of a String to a NumberĪll of the other tricks mentioned above that don't use parseInt, involve implicitly coercing the string into a number. The standard actually changed with ecmascript 5, so modern browsers no longer trigger octal when there's a leading 0 if no radix has been specified. The behaviour for hexadecimal is triggered by having the string start with 0x if no radix is specified, e.g. In older browsers, if the string started with a 0, it would be interpreted as octal if the radix wasn't specified which took a lot of people by surprise. It's good practice to always specify the radix as the second argument.
Here's an example of it doing something different to what you want, and giving no indication that anything went wrong: var widgetsSold = parseInt("97,800", 10) // widgetsSold is now 97 Whitespace at the beginning of the string is ignored. Parsing will stop silently if it hits a character it doesn't recognise, which can be useful for parsing strings like "92px", but it's also somewhat dangerous, since it won't give you any kind of error on bad input, instead you'll get back NaN unless the string starts with a number. ParseInt and parseFloat are the two functions used for parsing strings to numbers. You can also do the same thing explicitly with the Number function. unary plus) involve implicitly coercing the type of the string to a number. All of the tricks in the other answers (e.g. One way is to parse it and the other way is to change its type to a Number. There are two main ways to convert a string to a number in javascript. Interestingly, Math.round (like Math.floor) will do a string to number conversion, so if you want the number rounded (or if you have an integer in the string), this is a great way, maybe my favorite: var round = Math.round
If you're the type who forgets to put the radix in when you call parseInt, you can use parseFloat and round it however you like. Or, if you're going to be using Math.floor several times: var floor = Math.floor If your string is or might be a float and you want an integer: var x = Math.floor("1000.01") //floor automatically converts string to number If your string is already in the form of an integer: var x = +"1000" so you get a decimal number even with a leading 0 and an old browser () ParseInt: var x = parseInt("1000", 10) // you want to use radix 10 If that doesn't work for you, then there are the parseInt, unary plus, parseFloat with floor, and Math.round methods.
Convert string to integer code#
See the code example below.The simplest way would be to use the native Number function: var x = Number("1000") In the example below, we used autoboxing to convert int to an Integer object and see both variables hold the same value. Java supports autoboxing implicitly, so we don’t need to write any extra code. Convert Int to Integer Using Autoboxing in JavaĪutoboxing is a technique in which a primitive type gets converted into an object implicitly. In this article, we will learn to use these methods. If we want to convert primitive int to an Integer object, Java provides several methods such as valueOf() and Integer() constructors. Java uses either primitive int type or Integer wrapper class to hold integer values.
Convert string to integer how to#
This tutorial introduces how to convert primitive int to an integer object in Java. Convert Int to Integer Using the Integer.valueOf() Method in Java.Convert Int to Integer Using Integer Constructor in Java.Convert Int to Integer Using Autoboxing in Java.