Prefer that
for-in loops should include an if statement JS-0051
Anti-pattern
Minor
15 days ago
—
3 years old
Wrap the body of a for-in loop in an if statement with a hasOwnProperty guard
131 // Get the corresponding the definitions object from the componentAPI, convert to a spec object and return
132 let definition = ComponentAPI.getDefinitionForMINT(minttype);
133 let spec = [];
134 for (let key in definition.heritable) {135 let item = {136 min: definition.minimum[key],137 max: definition.maximum[key],138 value: definition.defaults[key],139 units: definition.units[key],140 steps: (definition.maximum[key] - definition.minimum[key]) / 10,141 name: key142 };143 spec.push(item);144 }145 return spec;
146 }
147 }Wrap the body of a for-in loop in an if statement with a hasOwnProperty guard
217 // Get the corresponding the definitions object from the componentAPI, convert to a spec object and return
218 let definition = ComponentAPI.getDefinition(threeduftype);
219 let spec = [];
220 for (let key in definition.heritable) {221 console.log(definition.units[key]);222 // const unittext = definition.units[key] !== "" ? he.htmlDecode(definition.units[key]) : "";223 let item = {224 mint: key,225 min: definition.minimum[key],226 max: definition.maximum[key],227 value: definition.defaults[key],228 units: definition.units[key],229 steps: (definition.maximum[key] - definition.minimum[key]) / 10,230 name: key231 };232 spec.push(item);233 }234 return spec;
235 },
236 showProperties() {Wrap the body of a for-in loop in an if statement with a hasOwnProperty guard
164 const heritable = def.heritable;
165 const defaults = def.defaults;
166
167 for (const key in heritable) {168 Registry.viewManager.adjustParams(typeString, setString, key, defaults[key]);169 }170 },
171
172 deleteButton() {Wrap the body of a for-in loop in an if statement with a hasOwnProperty guard
82 // Get the corresponding the definitions object from the componentAPI, convert to a spec object and return
83 let spec = [];
84 const definition = ComponentAPI.getDefinitionForMINT(mint);
85 for (let i in params.heritable) { 86 let key = params.heritable[i]; 87 let item = { 88 min: definition.minimum[key], 89 max: definition.maximum[key], 90 value: params.getValue(key), 91 units: definition.units[key], 92 steps: (definition.maximum[key] - definition.minimum[key]) / 10, 93 name: key 94 }; 95 spec.push(item); 96 } 97 console.log("Spec: ", spec);
98 return spec;
99 },Wrap the body of a for-in loop in an if statement with a hasOwnProperty guard
69 // Get the corresponding the definitions object from the componentAPI, convert to a spec object and return
70 let definition = ComponentAPI.getDefinition(threeduftype);
71 let spec = [];
72 for (let key in definition.heritable) {73 // const unittext = definition.units[key] !== "" ? he.htmlDecode(definition.units[key]) : "";74 let item = {75 mint: key,76 min: definition.minimum[key],77 max: definition.maximum[key],78 value: definition.defaults[key],79 units: definition.units[key],80 steps: (definition.maximum[key] - definition.minimum[key]) / 10,81 name: key82 };83 spec.push(item);84 }85 return spec;
86 }
87 }
Description
Looping over objects with a for in loop will include properties that are inherited through the prototype chain.
This behavior can lead to unexpected keys in your for loop.
Bad Practice
for (const key in foo) {
doSomething(key);
}
Recommended
for (const key in foo) {
if (Object.prototype.hasOwnProperty.call(foo, key)) {
doSomething(key);
}
}
for (const key of Object.keys(foo)) {
doSomething(key);
}