Chart.js-格式化 Y 轴

Here you can find a good example of how to format Y-Axis value.

Also, you can use scaleLabel : "<%=value%>" that you mentioned, It basically means that everything between <%= and %> tags will be treated as javascript code (i.e you can use if statments...)

As Nevercom said the scaleLable should contain javascript so to manipulate the y value just apply the required formatting.

Note the the value is a string.

var options = {
scaleLabel : "<%= value + ' + two = ' + (Number(value) + 2)   %>"
};

jsFiddle example

if you wish to set a manual y scale you can use scaleOverride

var options = {
scaleLabel : "<%= value + ' + two = ' + (Number(value) + 2)   %>",


scaleOverride: true,
scaleSteps: 10,
scaleStepWidth: 10,
scaleStartValue: 0


};

jsFiddle example

scaleLabel : "<%= Number(value).toFixed(2).replace('.', ',') + ' $'%>"

An undocumented feature of the ChartJS library is that if you pass in a function instead of a string, it will use your function to render the y-axis's scaleLabel.

So while, "<%= Number(value).toFixed(2).replace('.',',') + ' $' %>" works, you could also do:

scaleLabel: function (valuePayload) {
return Number(valuePayload.value).toFixed(2).replace('.',',') + '$';
}

If you're doing anything remotely complicated, I'd recommend doing this instead.

I had the same problem, I think in Chart.js 2.x.x the approach is slightly different like below.

ticks: {
callback: function(label, index, labels) {
return label/1000+'k';
}
}

More in details

var options = {
scales: {
yAxes: [
{
ticks: {
callback: function(label, index, labels) {
return label/1000+'k';
}
},
scaleLabel: {
display: true,
labelString: '1k = 1000'
}
}
]
}
}

Chart.js 2.X.X

I know this post is old. But if anyone is looking for more flexible solution, here it is

var options = {
scales: {
yAxes: [{
ticks: {
beginAtZero: true,
callback: function(label, index, labels) {
return Intl.NumberFormat().format(label);
// 1,350


return Intl.NumberFormat('hi', {
style: 'currency', currency: 'INR', minimumFractionDigits: 0,
}).format(label).replace(/^(\D+)/, '$1 ');
// ₹ 1,350


// return Intl.NumberFormat('hi', {
style: 'currency', currency: 'INR', currencyDisplay: 'symbol', minimumFractionDigits: 2
}).format(label).replace(/^(\D+)/, '$1 ');
// ₹ 1,350.00
}
}
}]
}
}

'hi' is Hindi. Check here for other locales argument
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl#Locale_identification_and_negotiation#locales_argument

for more currency symbol
https://www.currency-iso.org/en/home/tables/table-a1.html

For anyone using 3.X.X, here's the updated syntax to change y axis labels:

scales: {
y: {
ticks: {
callback: (label) => `$ ${label}`,
},
},
},