I have a string and need to check with and get whether the following strings overlap with the start and end of my target string:
target string: "click on the Run"
search strings: "the Run button to", "code and click on"
Apparently:
"the Run button to" is overlapped at the end of target "click on the Run"
"code and click on" is overlapped at the start of target "click on the Run"
Both, "the Run" and "click on" will be the desired results.
I have come up with a function to check and get the overlapped results for the cases at the start and at the end separately.
Question:
But my code could not be able to get the expected results only if I know how the search string overlapped with the target string in the very first place. And how can I combine the searched results in one go as well?
function findOverlapAtEnd(a, b) {
if (b.length === 2) {
return "";
}
if (a.indexOf(b) >= 0) {
return b;
}
if (a.endsWith(b)) {
return b;
}
return findOverlapAtEnd(a, b.substring(0, b.length - 1));
}
function findOverlapAtStart(a, b) {
if (b.length === 2) {
return "";
}
if (a.indexOf(b) >= 0) {
return b;
}
if (a.startsWith(b)) {
return b;
}
return findOverlapAtStart(a, b.substring(1));
}
console.log(findOverlapAtEnd("click on the Run", "the Run button to"))
console.log(findOverlapAtStart("click on the Run", "code and click on"))
edited:
case in the middle is also considered, e.g.:
target string: "click on the Run"
search strings: "on the"
Return value: "on the"
You may try this
function findOverlapAtEnd(a, b, min) {
if (b.length <= min) {
return '';
}
if (a.indexOf(b) >= 0) {
return b;
}
if (a.endsWith(b)) {
return b;
}
return findOverlapAtEnd(a, b.substring(0, b.length - 1), min);
}
function findOverlapAtStart(a, b, min) {
if (b.length <= min) {
return '';
}
if (a.indexOf(b) >= 0) {
return b;
}
if (a.startsWith(b)) {
return b;
}
return findOverlapAtStart(a, b.substring(1), min);
}
const GetOverlappingSection = (target, search, min) => {
if (target.length < search.length) {
const tmp = target;
target = search;
search = tmp;
}
let overlap1 = findOverlapAtStart(target, search, min);
if (overlap1.length === 0) {
overlap1 = findOverlapAtEnd(target, search, min);
}
return overlap1;
};
const removeEmptyKeyword = overlap => {
let tmpFinaloverlap = [];
overlap.forEach((key, idx) => {
if (!(key.trim().length === 0)) {
tmpFinaloverlap = [...tmpFinaloverlap, key];
}
});
return tmpFinaloverlap;
};
// let overlap = ['click on','the Run']
const GetOverlappingOfKeyowrd1And2 = (keywordSet1, keywordSet2,min) => {
let resultSetoverlap = [];
let tmpresultSetoverlap = [];
keywordSet1.forEach(key =>
keywordSet2.forEach(k2 => {
tmpresultSetoverlap = [
...tmpresultSetoverlap,
GetOverlappingSection(key, k2, min),
];
})
);
// get the resultSetoverlap
tmpresultSetoverlap.forEach(element => {
if (element.length > 0) {
resultSetoverlap = [...resultSetoverlap, element];
}
});
return resultSetoverlap;
};
const min = 2;
//To handle overlapping issue in overlapping set, that casuing
overlap.forEach((key, idx) => {
if (idx < overlap.length - 1) {
for (let i = idx + 1; i < overlap.length; i++) {
console.log(`key: ${key}`);
console.log(`search: ${overlap[i]}`);
let overlapSection = GetOverlappingSection(key, overlap[i], min);
if (overlapSection.length > 0) {
console.log(`overlapSection: ${overlapSection}`);
overlap[idx] = overlap[idx].replace(overlapSection, '');
}
}
}
});
overlap = removeEmptyKeyword(overlap);
console.log(overlap);
overlap.forEach(key => {
keywordSet2 = keywordSet2.map((k1, idx) => {
console.log(`checking overlap keyword:'${key}' in '${k1}'`);
return k1.replace(key, '');
});
});
overlap.forEach(key => {
keywordSet1 = keywordSet1.map((k1, idx) => {
console.log(`checking overlap keyword:'${key}' in '${k1}'`);
return k1.replace(key, '');
});
});
keywordSet2 = removeEmptyKeyword(keywordSet2);
keywordSet1 = removeEmptyKeyword(keywordSet1);
overlap.forEach(key => {
text = text.replace(key, `$#k1k2$&$`);
});
keywordSet1.forEach(key => {
text = text.replace(key, `$#k1$&$`);
});
keywordSet2.forEach(key => {
text = text.replace(key, `$#k2$&$`);
});
console.log(`ResultSetoverlap after processing:${text}`);
Because I need to decompress and I find these logic puzzles fun, here's my solution to the problem...
https://highdex.net/begin_end_overlap.htm
You can view source of the page to see JavaScript code I used. But just in case I ever take that page down, here's the important function...
function GetOverlappingSection(str1, str2, minOverlapLen = 4) {
var work1 = str1;
var work2 = str2;
var w1Len = work1.length;
var w2Len = work2.length;
var resultStr = "";
var foundResult = false;
var workIndex;
if (minOverlapLen < 1) { minOverlapLen = 1; }
else if (minOverlapLen > (w1Len > w2Len ? w2Len : w1Len)) { minOverlapLen = (w1Len > w2Len ? w2Len : w1Len); }
//debugger;
//we have four loops to go through. We trim each string down from each end and see if it matches either end of the other string.
for (var i1f = 0; i1f < w1Len; i1f++) {
workIndex = work2.indexOf(work1);
if (workIndex == 0 || (workIndex != -1 && workIndex == w2Len - work1.length)) {
//we found a match!
foundResult = true;
resultStr = work1;
break;
}
work1 = work1.substr(1);
if (work1.length < minOverlapLen) { break; }
}
if (!foundResult) {
//debugger;
//reset the work vars...
work1 = str1;
for (var i1b = 0; i1b < w1Len; i1b++) {
workIndex = work2.indexOf(work1);
if (workIndex == 0 || (workIndex != -1 && workIndex == w2Len - work1.length)) {
//we found a match!
foundResult = true;
resultStr = work1;
break;
}
work1 = work1.substr(0, work1.length - 1);
if (work1.length < minOverlapLen) { break; }
}
}
if (!foundResult) {
//debugger;
//reset the work vars...
work1 = str1;
for (var i2f = 0; i2f < w2Len; i2f++) {
workIndex = work1.indexOf(work2);
if (workIndex == 0 || (workIndex != -1 && workIndex == w1Len - work2.length)) {
//we found a match!
foundResult = true;
resultStr = work2;
break;
}
work2 = work2.substr(1);
if (work2.length < minOverlapLen) { break; }
}
}
if (!foundResult) {
//debugger;
//reset the work vars...
work2 = str2;
for (var i2b = 0; i2b < w2Len; i2b++) {
workIndex = work1.indexOf(work2);
if (workIndex == 0 || (workIndex != -1 && workIndex == w1Len - work2.length)) {
//we found a match!
foundResult = true;
resultStr = work2;
break;
}
work2 = work2.substr(0, work2.length - 1);
if (work2.length < minOverlapLen) { break; }
}
}
return resultStr;
}
Hopefully that's helpful.
Related
I did a generic method to sort both text and dates from my columns, however it does not filter the year, it is ignoring it considering only the month and day. The following method:
orderBy(header) {
let data = [...this.data];
if (this.orderByProperty === header.property) {
if (this.orderByType === "asc") {
this.orderByType = "desc";
} else {
this.orderByType = "asc";
}
data = data.reverse();
this.$emit("orderBy", data);
return;
}
this.orderByProperty = header.property;
this.orderByType = header.orderBy;
switch (header.property) {
case "active":
data.sort((a, b) => {
let comparison = 0;
if (a[header.property] < b[header.property]) {
comparison = 1;
} else if (a[header.property] > b[header.property]) {
comparison = -1;
}
//it has to return -1, 0 or 1
return comparison;
});
break;
case "name":
data.sort((a, b) => {
return a.name < b.name ? -1 : 1;
});
break;
default:
data.sort((a, b) => {
let valueA;
let valueB;
if (Array.isArray(a[header.property])) {
valueA = a[header.property].sort()[0];
valueB = b[header.property].sort()[0];
} else {
valueA = a[header.property] || "";
valueB = b[header.property] || "";
}
let comparison = 0;
if (isNaN(a[header.property])) {
if (a[header.property] == undefined) {
comparison = 1;
} else if (
a[header.property].length == 10 &&
this.moment(a[header.property], "DD/MM/YYYY").format(
"MM/DD/YYYY"
) >
this.moment(b[header.property], "DD/MM/YYYY").format(
"MM/DD/YYYY"
)
) {
comparison = 1;
} else if (
valueA.toLowerCase() > valueB.toLowerCase() &&
a[header.property].length != 10
) {
comparison = 1;
} else {
comparison = -1;
}
} else if (isDateString(valueA)) {
if (new Date(valueA) < new Date(valueB)) {
comparison = 1;
} else {
comparison = -1;
}
} else {
if (parseInt(a[header.property]) > parseInt(b[header.property])) {
comparison = 1;
} else {
comparison = -1;
}
}
//it has to return -1, 0 or 1
return comparison
})
break
}
this.$emit("orderBy", data)
return
}
I tried to change the ordering but it is ordering only by text.
The header sorts both by date and by text.
I want to create a function that is able to determine if a number is same or palindrome. if a given number is palindrome or same then return 2 otherwise if it is not palindrome or same then i need check it twice by increment the given number by 1. after that if it palindrome or same then return 1. if no palindrome or same number found then return 0. i write the function which is giving me the exact result when i give the number as 11211 but the function don't show any response if i enter 1122 or other random value. please help me to find where the error of my function.
function sameOrPalindrome(num) {
var c = 0;
var al = 0;
var normalArray = num.toString().split("");
var revArray = num.toString().split("").reverse();
for (var i = 0; i < normalArray.length; i++) {
if (normalArray[i] != revArray[i]) {
c++;
}
}
if (c == 0) {
return 2;
} else {
num++;
al = sameOrPalindrome(num);
if (al == 2) {
return 1;
} else {
num++;
al = sameOrPalindrome(num);
if (al == 2) {
return 1;
}
}
}
return 0;
}
console.log("1233",sameOrPalindrome(1233))
here is my solution to this problem:
function reversedNum(num) {
return (
parseFloat(
num
.toString()
.split('')
.reverse()
.join('')
) * Math.sign(num)
)
}
function sameOrPalindrome(num) {
if (num === reversedNum(num)) {
return 2;
} else {
num++;
if (num === reversedNum(num)) {
return 1;
} else {
num++;
if (num === reversedNum(num)) {
return 1;
}
}
}
return 0;
}
console.log("1233",sameOrPalindrome(1233))
Perhaps not using recurse - I think your function loops
const allEqual = arr => arr.every( v => v === arr[0] )
const sameOrPalin = num => {
const str = String(num);
let arr = str.split("")
if (allEqual(arr)) return 2
arr.reverse();
if (arr.join("") === str) return 1;
return 0
};
console.log("1111",sameOrPalin(1111));
console.log("2111",sameOrPalin(2111));
console.log("2112",sameOrPalin(2112));
console.log("1234",sameOrPalin(1234));
for (let i = 2111; i<=2113; i++) console.log(i,sameOrPalin(i));
Question: I assumed if palindrome test is true at first time then return 2. if not try incrementing by one and test the palindrome again . if true return 1 else try incrementing for last time and check the palindrome if true return 1 else 0.
Store string into array first and do arr.reverse().join("") to compare
let arr=num.toString().split("");
if(num.toString() == arr.reverse().join(""))
function sameOrPalindrome(num, times) {
let arr = num.toString().split("");
if (num.toString() == arr.reverse().join("")) {
if (times == 3) return 2
else return 1;
} else if (times > 0) {
num++; times--;
return sameOrPalindrome(num, times);
} else return 0
}
console.log(sameOrPalindrome(123321, 3));
console.log(sameOrPalindrome(223321, 3));
console.log(sameOrPalindrome(323321, 3));
Your function needs to know if it should not call itself any more, e.g. when it's doing the second and third checks:
function sameOrPalindrome(num,stop) { // <-- added "stop"
var c = 0;
var al = 0;
var normalArray = num.toString().split("");
var revArray = num.toString().split("").reverse();
for (var i = 0; i < normalArray.length; i++) {
if (normalArray[i] != revArray[i]) {
c++;
}
}
if (c == 0) {
return 2;
} else if(!stop) { // <-- check of "stop"
num++;
al = sameOrPalindrome(num,true); // <-- passing true here
if (al == 2) {
return 1;
} else {
num++;
al = sameOrPalindrome(num,true); // <-- and also here
if (al == 2) {
return 1;
}
}
}
return 0;
}
for(let i=8225;i<8230;i++)
console.log(i,sameOrPalindrome(i));
function check_palindrom(num){
var c1 = 0;
var normalArray = num.toString().split("");
var revArray = num.toString().split("").reverse();
for (var i = 0; i < normalArray.length; i++) {
if (normalArray[i] == revArray[i]) {
c1++;
}
}
if(c1==0){
return 2;
}else{
return 1;
}
}//check_palindrom
function my_fun_check_palindrome(mynum){
//console.log(mynum);
var num = mynum;
var c2 = 0;
var al = 0;
var normalArray = mynum.toString().split("");
var revArray = mynum.toString().split("").reverse();
for (var j = 0; j < normalArray.length; j++) {
if (normalArray[j] == revArray[j]) {
c2++;
}
}
if(c2==0){
console.log('Number is palindrome. Return Value :'+ 2);
}
if(1){
console.log('checking again with incremeting value my one');
num = parseInt(num)+1;
al = check_palindrom(num);
if(al==2){
console.log('Number is palindrome. Return Value :'+ 1);
}else{
console.log('Number is not palindrome. Return Value :'+ 0);
}
}
}//my_fun_check_palindrome
console.log(my_fun_check_palindrome(1122));
console.log(my_fun_check_palindrome(11221));
We should always strive to make function more effiecient... you dont need to run full loop. plus actual checking of palindrome can me modularized
function isSameOrPalindrome(num) {
var normalArray = num.toString().split("");
var revArray = num.toString().split("").reverse(),
i;
for (i = 0; i < normalArray.length / 2; i++) {
if (normalArray[i] !== revArray[i]) {
break;
}
}
if (i >= normalArray.length/2) {
return "Palindrome";
} else {
return "Not Palindrome";
}
}
function doCheck(num) {
var isPalindrome = isSameOrPalindrome(num);
console.log(isPalindrome);
if(isPalindrome === "Palindrome") {
return 2;
} else {
num++;
isPalindrome = isSameOrPalindrome(num);
if(isPalindrome === "Palindrome") {
return 1;
} else {
return 0
}
}
}
console.log("100",doCheck(100));
I have the next function:
function solveSudoku(prev_tab, fila, columna) {
let tab = _.cloneDeep(prev_tab);
let sig_fila = fila;
let sig_col = columna;
if (fila === 8 && columna === 8) {
//console.log(tab);
return tab;
}
if (columna === 8) {
sig_col = 0;
sig_fila = sig_fila + 1
} else {
sig_col = sig_col + 1;
}
if ((tab[fila][columna]) !== '') {
solveSudoku(tab, sig_fila, sig_col)
} else {
for (let num = 1; num <= 9; num++) {
if (numeroValido(tab, num, fila, columna)) {
tab[fila][columna] = num;
//tab.toString();
solveSudoku(tab, sig_fila, sig_col)
}
}
}
}
it returns undefined instead of a 2D array, i already try to add return in every recursive call =>
return solveSudoku( tab, sig_fila, sig_col )
but now that doesn't work either
I'm not really familiar with algorithms for solving sudoku, so I don't know if the algorithm below is correct.
But you need to ensure that the result of the recursion is returned. In my update below, I return the first recursive call. In the loop, I only return it if the recursion successfully found a solution, otherwise the loop continues trying other numbers in the column.
function solveSudoku(prev_tab, fila, columna) {
let tab = _.cloneDeep(prev_tab);
let sig_fila = fila;
let sig_col = columna;
if (fila === 8 && columna === 8) {
//console.log(tab);
return tab;
}
if (columna === 8) {
sig_col = 0;
sig_fila = sig_fila + 1
} else {
sig_col = sig_col + 1;
}
if ((tab[fila][columna]) !== '') {
return solveSudoku(tab, sig_fila, sig_col)
} else {
for (let num = 1; num <= 9; num++) {
if (numeroValido(tab, num, fila, columna)) {
tab[fila][columna] = num;
//tab.toString();
let result = solveSudoku(tab, sig_fila, sig_col);
if (result) { // continue searching if the recursion failed
return result;
}
}
}
}
}
I am making a custom registration page with only 2 values Email and Password, later I will add confirm password as well, for my password field I have some restrictions and I am using some regex and also some custom made code to make the validation.
this is my validateField:
validateField(fieldName, value) {
let fieldValidationErrors = this.state.formErrors;
let emailValid = this.state.emailValid;
let passwordValid = this.state.passwordValid;
//let passwordValidConfirm = this.state.passwordConfirmValid;
switch(fieldName) {
case 'email':
emailValid = value.match(/^([\w.%+-]+)#([\w-]+\.)+([\w]{2,})$/i);
fieldValidationErrors.email = emailValid ? '' : ' is invalid';
break;
case 'password':
passwordValid = (value.length >= 5 && value.length <= 32) && (value.match(/[i,o,l]/) === null) && /^[a-z]+$/.test(value) && this.check4pairs(value) && this.check3InRow(value);
fieldValidationErrors.password = passwordValid ? '': ' is not valid';
break;
default:
break;
}
this.setState({formErrors: fieldValidationErrors,
emailValid: emailValid,
passwordValid: passwordValid,
//passwordValidConfirm: passwordValidConfirm
}, this.validateForm);
}
as you can see for
passwordValid
I have made some methods, this one
check3InRow
doesnt work the way I want it to work, this one makes sure, you have at least 3 letters in your string that are in a row so like "abc" or "bce" or "xyz".
check3InRow(value){
var counter3 = 0;
var lastC = 0;
for (var i = 0; i < value.length; i++) {
if((lastC + 1) === value.charCodeAt(i)){
counter3++;
if(counter3 >= 3){
alert(value);
return true;
}
}
else{
counter3 = 0;
}
lastC = value.charCodeAt(i);
}
return false;
}
this doesnt work correctly so it should accept this:
aabcc
as a password but not:
aabbc
You are starting your counter from 0 and looking for greater than equal to 3 which will never be 3 for 3 consecutive characters. Rest everything is fine with your code.
check3InRow(value) {
var counter3 = 1;
var lastC = 0;
for (var i = 0; i < value.length; i++) {
if ((lastC + 1) === value.charCodeAt(i)) {
counter3++;
if (counter3 >= 3) {
alert(value);
return true;
}
} else {
counter3 = 1;
}
lastC = value.charCodeAt(i);
}
return false;
}
Can we not do a simple version of that function? Like
function check3InRow2(value){
for (var i = 0; i < value.length-2; i++) {
const first = value.charCodeAt(i);
const second = value.charCodeAt(i+1);
const third = value.charCodeAt(i+2);
if(Math.abs(second - first) === 1 && Math.abs(third-second) === 1){
return true;
}
}
return false;
}
I mean complexity wise it is O(N) so maybe we can give this a try
Also adding the your function. When you are AT a char then you should consider counter with 1. Because if another one matches it will be 2 consecutive values.
function check3InRow(value) {
var counter3 = 1;
var lastC = value.charCodeAt(0);
for (var i = 1; i < value.length; i++) {
if ((lastC + 1) === value.charCodeAt(i)) {
counter3++;
if (counter3 >= 3) {
return true;
}
} else {
counter3 = 1;
}
lastC = value.charCodeAt(i);
}
return false;
}
I wrote some functions involving prime factorization and I noticed that when I identified my test paragraph (for testing the results of functions and such) as document.getElementById("text"), it worked fine. However, when I declared a global variable text as var text = document.getElementById("text"), and then substituted in text for the longer version, it no longer worked. I did, however, notice that it worked when I locally declared text. Why is this and how can I fix it? My JSFiddle is here: https://jsfiddle.net/MCBlastoise/3ehcz214/
And this is my code:
var text = document.getElementById("text");
function isPrime(num) {
var lastDigit = parseInt((num + "").split("").reverse()[0]);
if (typeof num !== "number" || num <= 1 || num % 1 !== 0) {
return undefined;
}
else if (num === 2) {
return true;
}
else if (lastDigit === 0 || lastDigit === 2 || lastDigit === 4 || lastDigit === 5 || lastDigit === 6 || lastDigit === 8) {
return false;
}
else {
for (var i = 2; i < num; i++) {
if (num % i === 0) {
return false;
}
}
return true;
}
}
function factorSplit(dig) {
if (typeof dig !== "number" || dig <= 1 || dig % 1 !== 0) {
return undefined;
}
else if (dig === 2) {
return undefined;
}
else {
var factor;
for (var i = 2; i < dig; i++) {
if (dig % i === 0) {
factor = i;
break;
}
}
if (factor === undefined) {
return undefined;
}
else {
return [factor, (dig / factor)];
}
}
}
function allPrimes(arr) {
if (Array.isArray(arr) === false || arr.length < 1) {
return undefined;
}
else {
for (var i = 0; i < arr.length; i++) {
if (isPrime(arr[i]) !== true) {
return false;
}
}
return true;
}
}
function primeFactors(int) {
if (typeof int !== "number" || int <= 1) {
return undefined;
}
else if (isPrime(int) === true) {
return false;
}
else {
var initFactors = factorSplit(int);
while (allPrimes(initFactors) !== true) {
initFactors = initFactors.concat(factorSplit(initFactors[initFactors.length - 1]));
initFactors.splice((initFactors.length - 3), 1);
}
return initFactors;
}
}
function listPrimes() {
repeat = setInterval(findPrime, 1);
}
var primeInts = [2];
var check;
function findPrime() {
var i = primeInts[primeInts.length - 1] + 1;
if (check === undefined) {
check = true;
text.innerHTML = primeInts[0];
}
else {
while (isPrime(i) !== true) {
i++;
}
primeInts.push(i);
text.innerHTML += ", " + primeInts[primeInts.length - 1];
}
}
//text.innerHTML = isPrime(6);
<div onclick="listPrimes()" style="cursor:pointer; background-color:black; width:30px; height:30px"></div>
<p id="text"></p>
The text is global, you just need to make sure the whole script file is included in the html. Here's an example of what I mean
Here in code snippets stackoverflow does this for us already.
var text = document.getElementById("text");
function isPrime(num) {
var lastDigit = parseInt((num + "").split("").reverse()[0]);
if (typeof num !== "number" || num <= 1 || num % 1 !== 0) {
return undefined;
} else if (num === 2) {
return true;
} else if (lastDigit === 0 || lastDigit === 2 || lastDigit === 4 || lastDigit === 5 || lastDigit === 6 || lastDigit === 8) {
return false;
} else {
for (var i = 2; i < num; i++) {
if (num % i === 0) {
return false;
}
}
return true;
}
}
function factorSplit(dig) {
if (typeof dig !== "number" || dig <= 1 || dig % 1 !== 0) {
return undefined;
} else if (dig === 2) {
return undefined;
} else {
var factor;
for (var i = 2; i < dig; i++) {
if (dig % i === 0) {
factor = i;
break;
}
}
if (factor === undefined) {
return undefined;
} else {
return [factor, (dig / factor)];
}
}
}
function allPrimes(arr) {
if (Array.isArray(arr) === false || arr.length < 1) {
return undefined;
} else {
for (var i = 0; i < arr.length; i++) {
if (isPrime(arr[i]) !== true) {
return false;
}
}
return true;
}
}
function primeFactors(int) {
if (typeof int !== "number" || int <= 1) {
return undefined;
} else if (isPrime(int) === true) {
return false;
} else {
var initFactors = factorSplit(int);
while (allPrimes(initFactors) !== true) {
initFactors = initFactors.concat(factorSplit(initFactors[initFactors.length - 1]));
initFactors.splice((initFactors.length - 3), 1);
}
return initFactors;
}
}
function listPrimes() {
repeat = setInterval(findPrime, 1);
}
var primeInts = [2];
var check;
function findPrime() {
var i = primeInts[primeInts.length - 1] + 1;
if (check === undefined) {
check = true;
text.innerHTML = primeInts[0];
} else {
while (isPrime(i) !== true) {
i++;
}
primeInts.push(i);
text.innerHTML += ", " + primeInts[primeInts.length - 1];
}
}
function test() {
console.log("inside test1")
console.log(text);
text.innerHTML = "testtt"
}
function test2() {
console.log("inside test2")
console.log(text);
text.innerHTML = "testtt2"
}
text.innerHTML = isPrime(6);
<div onclick="test()" style="cursor:pointer; background-color:black; width:30px; height:30px"></div>
<p id="text"></p>
<div onclick="test2()" style="cursor:pointer; background-color:black; width:30px; height:30px"></div>
In the head the script runs/loads first and because you don't have the var's in a function they are never re-used they remain with the original value which is null since the document didn't exist at that time, then when the page loads all it has is access to the functions a call to the global var is null. This is why the code previously only worked when text = document.getElementById('text') was in a function.