diff --git a/String/CheckExceedingString.js b/String/CheckExceedingString.js
new file mode 100644
index 0000000000..70df38b515
--- /dev/null
+++ b/String/CheckExceedingString.js
@@ -0,0 +1,33 @@
+// checks if a string is exceeding string or not
+// Exceeding words are words where the gap between two adjacent characters is increasing.
+// The gap is the distance in ascii
+// More info at : https://github.com/TheAlgorithms/Javascript/issues/765
+
+/**
+ * a function to check whether a string is exceedng or not
+ * @param str the str that should be checked
+ */
+function checkExceedingString(str) {
+  if (typeof str !== 'string') throw new TypeError('str must be a string!')
+
+  const asciiArr = []
+
+  // collect the ascii of each letter
+  for (let s of str) asciiArr.push(s.charCodeAt())
+
+  let isExceeding = true
+
+  for (let j = 0; j < asciiArr.length - 3; j++) {
+    // if the ascii of current letter is greater than the next letter it's not an exceeding string
+    let gapCond =
+      Math.abs(asciiArr[j] - asciiArr[j + 1]) >
+      Math.abs(asciiArr[j + 2] - asciiArr[j + 3])
+    if (gapCond) {
+      isExceeding = false
+      break
+    }
+  }
+  return isExceeding
+}
+
+module.exports = checkExceedingString
diff --git a/String/test/CheckExceedingString.test.js b/String/test/CheckExceedingString.test.js
new file mode 100644
index 0000000000..3c1ad57dd8
--- /dev/null
+++ b/String/test/CheckExceedingString.test.js
@@ -0,0 +1,19 @@
+const checkExceedingString = require('./CheckExceedingString')
+
+describe('check exceeding string', () => {
+  it('expect to throw an error if input is not a string', () => {
+    expect(() => checkExceedingString(null)).toThrow()
+  })
+
+  it('expects to return true if the input is exceeding string', () => {
+    const value = 'abcdef'
+    const result = checkExceedingString(value)
+    expect(result).toBe(true)
+  })
+
+  it('expects to return false if the input is not in camel case format', () => {
+    const value = 'happy'
+    const result = checkExceedingString(value)
+    expect(result).toBe(false)
+  })
+})