If you want something a little more complex regarding format, you could use regex, something like this:. I created this regex while answering a different question awhile back see here.
This will check that it is a number with atleast one character, cannot start with 0 unless it is 0 or 0. Cannot have decimal unless there are digits after how to buy stocks without broker decimal, may or may not have commas. Could also add a -? This might be insane depending on the length of your string, but you could split it into an array of individual characters and then test each character with isNaN to determine if it's a number or not.
So this solution would reject '. But as long we stay in integer and low float number ranges, it should work with otherwise supplied numbers to.
No need to panic just use this snippet if name String Contains only numbers or text. A very short, wrong but correctable answer was just deleted. I just could comment it, besides it was very cool! So here the corrected term again:. The first term eliminates the empty string case, the second one enforces the string interpretataion of a number created by numeric interpretation of the string to match the string.
As the string is not empty, any tolerated character like whitespaces are removed, so we check if they were present. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams?
If one likes to accept, it can be trimmed first. What about numbers that don't fit in JS numbers for example ""? Show 1 more comment. Active Oldest Votes. Improve this answer. Sandeep 1, 6 6 gold badges 19 19 silver badges 32 32 bronze badges. Ramu Vemula Ramu Vemula 1 1 silver badge 3 how to make a template in dreamweaver bronze badges.
Add a comment. Dallas Dallas A straight forward solution, and adaptable to all number formats one would like to allow. On the other hand, quite elaborate for just checking a number Note that this would accept numbers that don't fit in a JS number. This may, or not, be desirable.
And it doesn't accept negative numbers. This is easy to fix, though. In fact, a lot of fixes are necessary, for example for "-1e3". Not everybody usesand. Not everybody uses groups of 3 digits. Show 2 more comments. Looks good Rejects empty, tailing and whitespace strings, accepts non-canonical floats like '. Thats exhausting. Maybe I give up and go with this solution anyway. I will also post my 'exact' solution, that enforces a canonical form of the number, which may make problems, but should be ok in my case.
Would evaluate true for all longer whitespace inputs. Kishan Vasoya Kishan Vasoya 6 6 silver badges 6 6 bronze badges. So here the corrected term again: n! Doesn't work for ' '.
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1) Check if an array contains a string
First, the map method makes every element in the colors array lowercase and returns a new array. Then, the includes method returns true because the result array contains the element 'green'. The following example shows how to use the includes method to check if an array contains a number:. The following example uses the includes method to check if an array contains an object:.
In this example, the list. In practice, instead of searching for a refenrence, you often search for objects by their property values. The isEqual function returns true if the first and second objects have the same number of properties with the same values. And the limitation of the isEqual function is that the order of properties of the compared objects must be the same. Note that the some library provides the function that allows you compare two objects by their property values.
The following uses the array. This tutorial shows you to check if an array contain a value, being a primtive value or object. Was this tutorial helpful? Yes No.