What is the meaning of number 1e5?

Question

I have seen in some codes that people define a variable and assign values like 1e-8 or 1e5.

for example

const int MAXN = 1e5 + 123;

What are these numbers? I couldn't find any thing on the web...

https://en.wikipedia.org/wiki/Scientific_notation#E_notation — chepner, Sep 08 '21 at 21:19

score 91 · Accepted Answer · edited Feb 25 '23 at 17:35

91

1e5 is a number expressed using scientific notation, specifically E notation, and it means 1 multiplied by 10 to the 5th power (the 'e' meaning 'exponent').

So 1e5 equals 1*100000 and is equal to 100000. The three notations are interchangeable meaning the same.

edited Feb 25 '23 at 17:35

wjandrea

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answered Oct 03 '14 at 06:59

PA.

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For more on the scientific notation, see http://en.wikipedia.org/wiki/Scientific_notation – Michael Dec 02 '14 at 22:05
Just to note, for Python, `1e5` and `100000` are slightly different in that one's a `float` and one's an `int`. But they are equal. – wjandrea Feb 25 '23 at 17:23

score 31 · Answer 2 · edited Feb 25 '23 at 17:21

31

1e5 means 1 × 10⁵.

Similarly, 12.34e-9 means 12.34 × 10⁻⁹.

Generally, AeB means A × 10^B.

edited Feb 25 '23 at 17:21

wjandrea

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answered Jul 27 '18 at 04:17

Yashwant Kumar

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This! I think people who say 1e5 is equal to 10 to the 5th power are giving an incomplete answer. So I like your answer: `1x10^5`. Thanks – Erik van de Ven Dec 19 '20 at 15:39

score 3 · Answer 3 · answered Oct 03 '14 at 06:59

3

this is scientific notation for 10^5 = 100000

answered Oct 03 '14 at 06:59

DaveG

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score 0 · Answer 4 · answered Oct 18 '17 at 01:42

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1e5 is 100000. 5 stand for the amount of zeros you add in behind that number. For example, lets say I have 1e7. I would put 7 zeros behind 1 so it will become 10,000,000. But lets say that the number is 1.234e6. You would still add 6 zeros at the end of the number so it's 1.234000000, but since there is that decimal, you would have to move it to the right 6 times since it's e6.

answered Oct 18 '17 at 01:42

user8793186

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`1.234e6` -> `1234000` – brandito Jul 23 '18 at 04:24
this is the one definition I had in mind, but it was confusing some times. The accepted answer is better, more precise. – Intelligent-Infrastructure Aug 26 '22 at 14:11

score 0 · Answer 5 · answered Jan 09 '23 at 04:29

0

The values like: 1e-8 or 1e5

means;

1e-8 = 1 * 10^(-8)

And

1e5 = 1 * 10

answered Jan 09 '23 at 04:29

Ashok Chhetri

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What is the meaning of number 1e5?

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