CODEWITHSUNDEEP
javascript
Lalit Singh Tanwar
Lalit Singh Tanwar

Reputation: 83

JavaScript expression explanation

console.log("1" - - "1" );

Why does the code give me the folloing output: 2

Upvotes: 2

Views: 92

Answers (4)

AT808
AT808

Reputation: 28

This is just two strings being cast as numbers and subtracted. Essentially:

1 - -1

Or 2.

console.log(1 - - 1); 
console.log("1" - - "1");

for reference Auto-type conversion in JavaScript

Upvotes: 1

jgodi001
jgodi001

Reputation: 1

Another explanation besides the ones above is that JS has 'forced type conversion', and your expression is essentially trying to subtract a string from another string.

Try a method that converts the strings to numbers so you have more control over the type conversion and the output is more in-line with what you're expecting.

Upvotes: 0

Luca Kiebel
Luca Kiebel

Reputation: 10096

Well, if you subtract -1 from 1 you get 2, simple math, and that's what JavaScript does too.

JavaScript converts the strings you give it into numbers and then runs the calculation. 

console.log(1 - - 1);
console.log(1 - - 2); 
console.log(1 - - 3);
console.log(1 - - 155);

Upvotes: 0

marvel308
marvel308

Reputation: 10458

this string is equivalent to 

1 - (-1)

since javascript converts the string to numbers for you try running the code snippet 

console.log(- "1");
console.log(1 - "1");
console.log(1 - - "1");
console.log("1" - - "1");

Upvotes: 0

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