Typescript primitive data type conversion
Number and String are basic primitive data types in typescript programming language. The number to String and String to Number conversion are one of the simple tasks of typescript developers. For conversion to number, String must contain only numbers.The number to String conversion examples.
We can do many ways to achieve this.1 Append with an empty string.
2. toString() method
3. using string() method
Append with an empty string.
number values are 11,13. add an empty string to Number value returns a string object typeof method checks value type and returns primitive type as a stringvar a: number = 12
var str: string = a + '';
console.log(typeof (a)) // outpus number as output
console.log(typeof (str)) // outpus string as output
console.log(str) //outputs 12 as string value
var a: number = null
var str: string = a + '';
console.log(typeof (str)) // outpus string as output
console.log(str) //outputs null in the form of string
var a: number = undefined
var str: string = a + '';
console.log(typeof (str)) // outpus string as output
console.log(str) //outputs undefined in the form of string
toString() method
calling toString() method on any data types returns string objectvar a: number = 17
var str: string = a .toString()
console.log(typeof (str)) // outpus string as output
console.log(a) //outputs 12 as string value
if we use null and undefined with toString() method, compiler through 'Cannot read property 'toString' of null' error
string() method
this is the easiest way of a convert to string methodvar a: number = 12
var stringValue = String(a);
console.log(typeof(stringValue) // outpus string as output
String to Number example
This conversion can be achieved using various approaches1. parseInt
2. parseFloat
3. Number()
parseInt() and parseFloat() method
parseInt and parseFloat methods take input number in the form of a string and return numberconsole.log(parseInt('32', 10)) // outpus 32 as output
console.log(parseInt('45')) // outpus 45 as outpu
console.log(parseInt('45abc')) // outpus 45 as output
console.log(parseInt('null')) // outpus NaN as output
console.log(parseFloat('32.32')) // outpus 32.32 as output
console.log(parseInt('45')) // outpus 45 as output
Number() method
Number() constructor takes a string as a parameter and returns number as outputconsole.log(Number('12')) // outpus 12 as output
console.log(Number('null')) // outpus NaN as output
console.log(Number('undefined')) // outpus NaN as output
This is understanding on primitive types conversion in typescript language.
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