I have an array var data=["test","10%","abc","20%"];
Now is there any way so that i can filter out and get only the numbers something like result=["10%","20%"];
4 Answers
You can use this function:
Explanation: We create a new array and push
all the elements of the old array,
if the first letter
can be converted into a digit.
var data = ["test", "10%", "abc", "20%"];
function onlyNumbers(array) {
var newArr = [];
array.forEach(function(e) {
if (parseInt(e.charAt(0))) {
newArr.push(e);
}
})
return newArr;
}
var dataNew = onlyNumbers(data); // <-- ["10%","20%"]
document.write(JSON.stringify(dataNew));5 Comments
user1076698
Thanks for the solution , you got the question right and got me what i needed
henrikmerlander
This will include items such as "1xyz%", "2/()abs" and so on... You only check that the first character is a number.
John
@henrikmerlander That is correct. It is only a solution for this type of scenario. If the question or the situation would be more specific, we would have to modify the code.
henrikmerlander
Yeah it was just a heads up to the person accepting the answer. Maybe it is not the solution right away but a hint on how to do it. I still think the best solution is to use a regular expression though.
user1076698
@henrikmerlander yup,I was stuck with this problem,and John gave me an idea how can I achieve it.. As you said using regex will always be better
This will work out your problem and create new array with only good elements:
function check_percentage(num){
var regex = /^(\d+%)$/;
if (num.match(regex)){
return true;
}
}
var result=["babab","fg210%","120%","babab","4214210%","20%"],
filtered_result=[];
result.forEach(function(k,v){
if (check_percentage(k)){
filtered_result.push(k);
}
});
console.log(filtered_result);
Comments
You can use an underscore library and do:
var data=["test","10%","abc","20%"];
var result = _.filter(data, function(item) {
return item.match(/^(\d+|\d+[.]\d+)%?$/);
});
document.write(JSON.stringify(result));<script src="http://underscorejs.org/underscore-min.js"></script>And you can do the same without external library:
var data=["test","10%","abc","20%"],
result = [];
for(var i = 0; i < data.length; i++) {
if (data[i].match(/^(\d+|\d+[.]\d+)%?$/)) {
result.push(data[i]);
}
}
document.write(JSON.stringify(result));
1 Comment
teran
no need to use any libraries, pure JS
RegExp object has exec method, which does the same.var data = ["test", "10%", "abc", "20%"];
var result = [];
data.forEach(function(v) {
if (parseInt(v) > 0) result.push(parseInt(v));
});
console.log(result);If you need not the numbers but the string values, then just replace: result.push(parseInt(v)); => result.push(v);
%symbol? Have you tried writing a regular expression for that and using it with Array#filter?data.filter(parseInt);fails ?Array#filterpasses three arguments, the second of which is the index of the element being tested and which will be interpreted byparseIntas a radix. As for the approach of usingparseIntin general: I never said it was wrong. It’s hard to know what’s right. Usingif (parseInt(e))will fail if you didn’t want negative numbers, or if you did want zero, or if you didn’t want strings like0xf, or if you didn’t want strings like7#?zQl, or if you wanted0.5%.