I have strings that I have to insert in a db but I want to first modify their value if they fall under certain conditions.
For example I have the strings Epatite, Epatite B, EpatiteáB, EpB3 that I want them to be changed to EP B before being inserted into the db.
This is piece of my code:
// vaccines[index] is the string to compare
var vac = makeUniform(vaccines[index]);
const queryInsert = {
text: 'INSERT INTO coverages (vaccine) VALUES ($1) ON CONFLICT DO NOTHING;',
values: [vac]
}
var printText = '[INSERT Italy IN coverages]';
promises.push(postgreSQLlib.query(queryInsert, printText, false));
function makeUniform(val) {
if(val === 'DIF' || val === 'Difterite') {
return 'DIPH'; // diphtheria
}
else if(val === 'Epatite' || val === 'Epatite B' || val === 'EpatiteáB' || val === 'EpB3') {
return 'EP B'; // hepatitis B
}
else if(val === 'HIB' || val === 'Hib3' || val === 'Hib') {
return 'HIB'; // haemophilus influenzae B
}
else {
return val;
}
}
Whene I execute SELECT DISTINCT vaccine FROM coverages ORDER BY vaccine; on psql shell, I get:
DIPH
DT-DTP3
DTP3
EP A
EP B
EpatiteáB
Hib
HIB
M-MPR1
M-MPR1-MPRV ...
There is EpatiteáB which theoretically should have changed in EP B.
Why it doesn't work?
EDIT 1
vaccines[index] comes from an online pdf of which I did web scraping using the textract package of Node.js.
Thanks
Try to clean your development database first with this:
UPDATE coverages set vaccine = 'EP B' WHERE vaccine LIKE 'Epatite%' OR vaccine = 'EpB3';
Do something similar for the others.
Try this added one more condition = (val==="Epatite%E1B%21")
function makeUniform(val) {
if(val === 'DIF' || val === 'Difterite') {
return 'DIPH'; // diphtheria
}
else if(val === 'Epatite' || val === 'Epatite B' || val==="Epatite%E1B%21" || val === 'EpatiteáB' || val === 'EpB3') {
return 'EP B'; // hepatitis B
}
else if(val === 'HIB' || val === 'Hib3' || val === 'Hib') {
return 'HIB'; // haemophilus influenzae B
}
else {
return val;
}
}
I have an If statement that using || with an && operator e.g if((a || b) && c) however it is only works with the first condition i.e a but not with second i.e b even though running the debugger I can see that the condition is met and it goes to the correct line of code. Is there a better way to get this to work on both conditions?
code I have now:
function _getCatFormGUID(catName) {
debugger;
var dept = Browser.getValue(getElement("126D81CA203C21CF014C8A3550227892FE4B4A6A"));
if((catName == '1' && dept == "Entwicklung") || (catName == '7' && dept == "Entwicklung")){
return "A270AE7F957A74EF0842403EEA0032017567F3E8";
}
if((catName == '1' && dept != "Entwicklung") || (catName == '7' && dept != "Entwicklung")) {
return "8EDD0768A7CDF8FD8AE90DB473F41EF0B33FA14F";
}
return "";}
I have tried the following also:
if((catName == '1' || catName == '7') && dept == "Entwicklung"){
return "A270AE7F957A74EF0842403EEA0032017567F3E8";
}
and
if(catName == '1' && dept == "Entwicklung"){
return "A270AE7F957A74EF0842403EEA0032017567F3E8";
}
if(catName == '7' && dept == "Entwicklung"){
return "A270AE7F957A74EF0842403EEA0032017567F3E8";
}
It only returns for catName =='1'.
If I understood your problem correctly, I will write your first bit of code as bellow
function _getCatFormGUID(catName) {
var dept = Browser.getValue(getElement("126D81CA203C21CF014C8A3550227892FE4B4A6A"));
if (catName == '1' || catName == '7') {
if(dept == 'Entwicklung'){
return "A270AE7F957A74EF0842403EEA0032017567F3E8";
}
else{
return "8EDD0768A7CDF8FD8AE90DB473F41EF0B33FA14F";
}
}
else{
return "";
}
}
The problem is that you have to understand how those 2 logical operators do the comparison: because your first condition catName == '1' is true, it will never go to second conditions from the first parenthesis nor in the second paranthesis.Given your example, you might rewrite your logical condition from:
if((catName == '1' && dept == "Entwicklung") || (catName == '7' && dept == "Entwicklung")){
return "A270AE7F957A74EF0842403EEA0032017567F3E8";
}
to
if(dept == "Entwicklung" && catName == '1' || catName == '7'){ return something; }
}
See the bottom of this post;
function isVowel(aCharacter)
{
return ((aCharacter == 'a') || (aCharacter == 'A')||
(aCharacter == 'e') || (aCharacter == 'E')||
(aCharacter == 'i') || (aCharacter == 'I')||
(aCharacter == 'o') || (aCharacter == 'O')||
(aCharacter == 'u') || (aCharacter == 'U')||
(aCharacter == 'y') || (aCharacter == 'Y'));
}
function myF(aString)
{
// variable to hold resultString
var resultString = '';
// variable to hold the current and previous characters
var currentCharacter = '';
var precedingCharacter = '';
// in the case of the first character in the string there is no
// previous character, so we assign an empty string '' to the variable at first
//precedingCharacter = '';
// TODO part (ii)
// add code as directed in the question
var i = 0;
for( i; i < sString.length; ++i)
{
currentCharacter = sString.charAt(i);
if (isVowel(currentCharacter) && (!isVowel(precedingCharacter)))
{
resultString = resultString + 'ub';
}
resultString = resultString + currentCharacter;
precedingCharacter = currentCharacter;
}
return resultString;
}
var string1 = "the cat sat on the mat";
var result1 = myF(string1);
document.write(string1);//THIS ISN'T GOING TO BE DISPLAYED, BUT WHY?
document.write('<BR>');
document.write(result1);
You iterate on sString wich doesn't exist and not on your parameter aString.
Where is sString being declared in your function? Try with aString (or declare var sString = aString) and try again.
Please change function myF(aString) to function myF(sString)
There is a naming mistake. Here is a working copy of your code .
http://jsfiddle.net/hXarY/
You can try using "firebug" to catch such errors if you do not already do.
function isVowel(aCharacter)
{
return ((aCharacter == 'a') || (aCharacter == 'A')||
(aCharacter == 'e') || (aCharacter == 'E')||
(aCharacter == 'i') || (aCharacter == 'I')||
(aCharacter == 'o') || (aCharacter == 'O')||
(aCharacter == 'u') || (aCharacter == 'U')||
(aCharacter == 'y') || (aCharacter == 'Y'));
}
function myF(sString) // this should be sString , not aString
{
// variable to hold resultString
var resultString = '';
// variable to hold the current and previous characters
var currentCharacter = '';
var precedingCharacter = '';
// in the case of the first character in the string there is no
// previous character, so we assign an empty string '' to the variable at first
//precedingCharacter = '';
// TODO part (ii)
// add code as directed in the question
var i = 0;
for( i; i < sString.length; ++i)
{
currentCharacter = sString.charAt(i);
if (isVowel(currentCharacter) && (!isVowel(precedingCharacter)))
{
resultString = resultString + 'ub';
}
resultString = resultString + currentCharacter;
precedingCharacter = currentCharacter;
}
return resultString;
}
var string1 = "the cat sat on the mat";
var result1 = myF(string1);
document.write(string1);//THIS ISN'T GOING TO BE DISPLAYED, BUT WHY?
document.write('<BR>');
document.write(result1);
This question already has answers here:
How can I convert a string to boolean in JavaScript?
(102 answers)
Closed 4 years ago.
JavaScript has parseInt() and parseFloat(), but there's no parseBool or parseBoolean method in the global scope, as far as I'm aware.
I need a method that takes strings with values like "true" or "false" and returns a JavaScript Boolean.
Here's my implementation:
function parseBool(value) {
return (typeof value === "undefined") ?
false :
// trim using jQuery.trim()'s source
value.replace(/^\s+|\s+$/g, "").toLowerCase() === "true";
}
Is this a good function? Please give me your feedback.
Thanks!
I would be inclined to do a one liner with a ternary if.
var bool_value = value == "true" ? true : false
Edit: Even quicker would be to simply avoid using the a logical statement and instead just use the expression itself:
var bool_value = value == 'true';
This works because value == 'true' is evaluated based on whether the value variable is a string of 'true'. If it is, that whole expression becomes true and if not, it becomes false, then that result gets assigned to bool_value after evaluation.
You can use JSON.parse for that:
JSON.parse("true"); //returns boolean true
It depends how you wish the function to work.
If all you wish to do is test for the word 'true' inside the string, and define any string (or nonstring) that doesn't have it as false, the easiest way is probably this:
function parseBoolean(str) {
return /true/i.test(str);
}
If you wish to assure that the entire string is the word true you could do this:
function parseBoolean(str) {
return /^true$/i.test(str);
}
You can try the following:
function parseBool(val)
{
if ((typeof val === 'string' && (val.toLowerCase() === 'true' || val.toLowerCase() === 'yes')) || val === 1)
return true;
else if ((typeof val === 'string' && (val.toLowerCase() === 'false' || val.toLowerCase() === 'no')) || val === 0)
return false;
return null;
}
If it's a valid value, it returns the equivalent bool value otherwise it returns null.
You can use JSON.parse or jQuery.parseJSON and see if it returns true using something like this:
function test (input) {
try {
return !!$.parseJSON(input.toLowerCase());
} catch (e) { }
}
last but not least, a simple and efficient way to do it with a default value :
ES5
function parseBool(value, defaultValue) {
return (value == 'true' || value == 'false' || value === true || value === false) && JSON.parse(value) || defaultValue;
}
ES6 , a shorter one liner
const parseBool = (value, defaultValue) => ['true', 'false', true, false].includes(value) && JSON.parse(value) || defaultValue
JSON.parse is efficient to parse booleans
Personally I think it's not good, that your function "hides" invalid values as false and - depending on your use cases - doesn't return true for "1".
Another problem could be that it barfs on anything that's not a string.
I would use something like this:
function parseBool(value) {
if (typeof value === "string") {
value = value.replace(/^\s+|\s+$/g, "").toLowerCase();
if (value === "true" || value === "false")
return value === "true";
}
return; // returns undefined
}
And depending on the use cases extend it to distinguish between "0" and "1".
(Maybe there is a way to compare only once against "true", but I couldn't think of something right now.)
Why not keep it simple?
var parseBool = function(str) {
if (typeof str === 'string' && str.toLowerCase() == 'true')
return true;
return (parseInt(str) > 0);
}
You can add this code:
function parseBool(str) {
if (str.length == null) {
return str == 1 ? true : false;
} else {
return str == "true" ? true : false;
}
}
Works like this:
parseBool(1) //true
parseBool(0) //false
parseBool("true") //true
parseBool("false") //false
Wood-eye be careful.
After looking at all this code, I feel obligated to post:
Let's start with the shortest, but very strict way:
var str = "true";
var mybool = JSON.parse(str);
And end with a proper, more tolerant way:
var parseBool = function(str)
{
// console.log(typeof str);
// strict: JSON.parse(str)
if(str == null)
return false;
if (typeof str === 'boolean')
{
if(str === true)
return true;
return false;
}
if(typeof str === 'string')
{
if(str == "")
return false;
str = str.replace(/^\s+|\s+$/g, '');
if(str.toLowerCase() == 'true' || str.toLowerCase() == 'yes')
return true;
str = str.replace(/,/g, '.');
str = str.replace(/^\s*\-\s*/g, '-');
}
// var isNum = string.match(/^[0-9]+$/) != null;
// var isNum = /^\d+$/.test(str);
if(!isNaN(str))
return (parseFloat(str) != 0);
return false;
}
Testing:
var array_1 = new Array(true, 1, "1",-1, "-1", " - 1", "true", "TrUe", " true ", " TrUe", 1/0, "1.5", "1,5", 1.5, 5, -3, -0.1, 0.1, " - 0.1", Infinity, "Infinity", -Infinity, "-Infinity"," - Infinity", " yEs");
var array_2 = new Array(null, "", false, "false", " false ", " f alse", "FaLsE", 0, "00", "1/0", 0.0, "0.0", "0,0", "100a", "1 00", " 0 ", 0.0, "0.0", -0.0, "-0.0", " -1a ", "abc");
for(var i =0; i < array_1.length;++i){ console.log("array_1["+i+"] ("+array_1[i]+"): " + parseBool(array_1[i]));}
for(var i =0; i < array_2.length;++i){ console.log("array_2["+i+"] ("+array_2[i]+"): " + parseBool(array_2[i]));}
for(var i =0; i < array_1.length;++i){ console.log(parseBool(array_1[i]));}
for(var i =0; i < array_2.length;++i){ console.log(parseBool(array_2[i]));}
I like the solution provided by RoToRa (try to parse given value, if it has any boolean meaning, otherwise - don't). Nevertheless I'd like to provide small modification, to have it working more or less like Boolean.TryParse in C#, which supports out params. In JavaScript it can be implemented in the following manner:
var BoolHelpers = {
tryParse: function (value) {
if (typeof value == 'boolean' || value instanceof Boolean)
return value;
if (typeof value == 'string' || value instanceof String) {
value = value.trim().toLowerCase();
if (value === 'true' || value === 'false')
return value === 'true';
}
return { error: true, msg: 'Parsing error. Given value has no boolean meaning.' }
}
}
The usage:
var result = BoolHelpers.tryParse("false");
if (result.error) alert(result.msg);
stringjs has a toBoolean() method:
http://stringjs.com/#methods/toboolean-tobool
S('true').toBoolean() //true
S('false').toBoolean() //false
S('hello').toBoolean() //false
S(true).toBoolean() //true
S('on').toBoolean() //true
S('yes').toBoolean() //true
S('TRUE').toBoolean() //true
S('TrUe').toBoolean() //true
S('YES').toBoolean() //true
S('ON').toBoolean() //true
S('').toBoolean() //false
S(undefined).toBoolean() //false
S('undefined').toBoolean() //false
S(null).toBoolean() //false
S(false).toBoolean() //false
S({}).toBoolean() //false
S(1).toBoolean() //true
S(-1).toBoolean() //false
S(0).toBoolean() //false
I shamelessly converted Apache Common's toBoolean to JavaScript:
JSFiddle: https://jsfiddle.net/m2efvxLm/1/
Code:
function toBoolean(str) {
if (str == "true") {
return true;
}
if (!str) {
return false;
}
switch (str.length) {
case 1: {
var ch0 = str.charAt(0);
if (ch0 == 'y' || ch0 == 'Y' ||
ch0 == 't' || ch0 == 'T' ||
ch0 == '1') {
return true;
}
if (ch0 == 'n' || ch0 == 'N' ||
ch0 == 'f' || ch0 == 'F' ||
ch0 == '0') {
return false;
}
break;
}
case 2: {
var ch0 = str.charAt(0);
var ch1 = str.charAt(1);
if ((ch0 == 'o' || ch0 == 'O') &&
(ch1 == 'n' || ch1 == 'N') ) {
return true;
}
if ((ch0 == 'n' || ch0 == 'N') &&
(ch1 == 'o' || ch1 == 'O') ) {
return false;
}
break;
}
case 3: {
var ch0 = str.charAt(0);
var ch1 = str.charAt(1);
var ch2 = str.charAt(2);
if ((ch0 == 'y' || ch0 == 'Y') &&
(ch1 == 'e' || ch1 == 'E') &&
(ch2 == 's' || ch2 == 'S') ) {
return true;
}
if ((ch0 == 'o' || ch0 == 'O') &&
(ch1 == 'f' || ch1 == 'F') &&
(ch2 == 'f' || ch2 == 'F') ) {
return false;
}
break;
}
case 4: {
var ch0 = str.charAt(0);
var ch1 = str.charAt(1);
var ch2 = str.charAt(2);
var ch3 = str.charAt(3);
if ((ch0 == 't' || ch0 == 'T') &&
(ch1 == 'r' || ch1 == 'R') &&
(ch2 == 'u' || ch2 == 'U') &&
(ch3 == 'e' || ch3 == 'E') ) {
return true;
}
break;
}
case 5: {
var ch0 = str.charAt(0);
var ch1 = str.charAt(1);
var ch2 = str.charAt(2);
var ch3 = str.charAt(3);
var ch4 = str.charAt(4);
if ((ch0 == 'f' || ch0 == 'F') &&
(ch1 == 'a' || ch1 == 'A') &&
(ch2 == 'l' || ch2 == 'L') &&
(ch3 == 's' || ch3 == 'S') &&
(ch4 == 'e' || ch4 == 'E') ) {
return false;
}
break;
}
default:
break;
}
return false;
}
console.log(toBoolean("yEs")); // true
console.log(toBoolean("yES")); // true
console.log(toBoolean("no")); // false
console.log(toBoolean("NO")); // false
console.log(toBoolean("on")); // true
console.log(toBoolean("oFf")); // false
Inspect this element, and view the console output.
Enough to using eval javascript function to convert string to boolean
eval('true')
eval('false')