EN
JavaScript - round with precision using arrow function in ES6
6 points
In this short article, we would like to show how to write arrow function that rounds numbers with precision up to n decimal places in modern JavaScript (>= ES6)
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const round = (value, precision) => {2
const power = Math.pow(10, precision);3
return Math.round(value * power) / power;4
};5
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// Usage example:7
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console.log( round( 5 , 0 ) ); // 59
console.log( round( 5. , 0 ) ); // 510
console.log( round( .5, 0 ) ); // 111
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console.log( round( 1.2345, 0 ) ); // 113
console.log( round( 1.2345, 1 ) ); // 1.214
console.log( round( 1.2345, 2 ) ); // 1.2315
console.log( round( 1.2345, 3 ) ); // 1.23516
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console.log( round( -1.2345, 0 ) ); // -118
console.log( round( -1.2345, 1 ) ); // -1.219
console.log( round( -1.2345, 2 ) ); // -1.2320
console.log( round( -1.2345, 3 ) ); // -1.23421
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console.log( round( 12345, -1 ) ); // 1235023
console.log( round( 12345, -2 ) ); // 1230024
console.log( round( 12345, -3 ) ); // 12000