PYTHON

check if string contains substring

Like this:

if (str.indexOf("Yes") >= 0)
...or you can use the tilde operator:

if (~str.indexOf("Yes"))
This works because indexOf() returns -1 if the string wasn't found at all.

Note that this is case-sensitive.
If you want a case-insensitive search, you can write

if (str.toLowerCase().indexOf("yes") >= 0)
Or:

if (/yes/i.test(str))

check if string is substring of another string

function mutation(arr) {
  let first = arr[0];
  let second = arr[1];
  
  return first.indexOf(second) !== -1;
}

console.log(mutation(["hello", "hel"]));

Find If String Is Substring Of Another

#is target in base?

def findSubstring(base, target):
   match = ""
   for x in range(0, len(base)):
       substring = base[0:len(base)-x]
       if substring == target:
           print("there is a match")
           match = substring
            
   if match == "":
     return ""
   else:
     return match
      


print(findSubstring("aaaaaaa", "aaa"))